Three Equations, Three Unknowns

Algebra Level 1

x + y = 10 y + z = 20 z + x = 24 \begin{array} { l l } x+y & =10 \\ y+z & =20 \\ z+x& =24 \\ \end{array}

What is the value of x + y + z x + y + z ?


The answer is 27.

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99 solutions

Discussions for this problem are now closed

Lim Zi Heng
Dec 25, 2013

( x + y ) + ( y + z ) + ( z + x ) = 10 + 20 + 24 (x + y) + (y + z) + (z + x) = 10 + 20 + 24

2 x + 2 y + 2 z = 54 2x + 2y + 2z = 54

2 ( x + y + z ) = 54 2 (x + y + z) = 54

x + y + z = 27 x + y + z = 27

Nice. Simple and short. But I solve with long calculation.

Shi Qin Yew - 7 years, 4 months ago

(x+y)+(y+z)+(z+x)=10+20+24 2(x+y+z)=54 x+y+z=27

aneela ammulu - 7 years, 4 months ago

hoaaah,cool

Dhafin Rizqaar - 7 years, 1 month ago

Where did you get the 2 from ? Why is it important ?

moftah dhafr - 7 years, 5 months ago

he gets it from combining similar variables or terms such as x+x=2x,y+y=2y,and z+z=2z.

carl1 espinosa - 7 years, 5 months ago

right.. Mr..LIM Ji

RH Badhon - 7 years, 5 months ago

cool... i really like your solution though i have different one...

Julius Rameses Martinez - 7 years, 5 months ago

ya righht

Syed Naseem Shah - 7 years, 5 months ago

add first 2 equations and then solve the equation we got with the third one

Iqbal Bhatti - 7 years, 5 months ago

Very well solved.Quite easy to understand.

MUBEEN TAJ - 7 years, 4 months ago

cool

Anupam Tiwari - 7 years, 4 months ago

AWtss

Kirk Hammet - 7 years, 4 months ago

Best solution...

Heder Oliveira Dias - 7 years, 4 months ago

it was very easy to answer

somarouthu chaturya - 7 years, 3 months ago

2(x+y+z)=54 , x+y+z=54/2 , x+y+z=27.

Syed Mostasim Saif - 7 years, 1 month ago

wow I used a lot of formulas but still couldn't

Chirstian Addoh - 7 years, 1 month ago

(z+y)-(y+x)=z-x=10 (z+x)-(z-x)=2x=14 \ x=7 \z+7=24 \z=17 \y+17=20 \y=3 \y+z+x=27

as simple as that. You don't even need to find the missing numbers...

Jeremy Bansil - 7 years, 3 months ago
Nit Jon
Dec 25, 2013

First add all the equations...

( x + y ) + ( y + z ) + ( z + x ) = 10 + 20 + 24 (x+y)+(y+z)+(z+x)=10+20+24

2 x + 2 y + 2 z = 54 2x+2y+2z=54

Then you see that the two is common in the whole equation and divide the whole equation by two...

2 ( x + y + z ) = 54 2(x+y+z)=54

x + y + z = 54 / 2 x+y+z=54/2

x + y + z = 27 x+y+z=27

And there is your answer...

Kamran Anjum
Dec 25, 2013

if we add these three equation then

x+y+y+z+z+x=10+20+24

2x+2y+2z=54

2(x+y+z)=54

x+y+z= 54/2

x+y+z=27

I think this is the best way to do that. Excellent

Amit Bhagat - 7 years, 5 months ago
Mohammad Al Ali
Dec 25, 2013

If we add the three equations,

x + y = 10 (1).

y + z = 20 (2).

z + x = 24 (3).

Adding (1) (2) (3) together we obtain:

2x + 2y + 2z = 54

Thus, dividing by 2 we obtain:

x + y + z = 27

Hence the answer is 27

Maria Felicita
Dec 25, 2013

First

X + Y = 10

Y + Z = 20

Z + X = 24

Second

Z - Y = 14

Z + Y = 20

2 Z = 34

Third

Z = 17

Y = 3

X = 7

X+Y+Z = 27 \boxed{27}

Can you please explain hoe you did it?

Chirstian Addoh - 7 years, 1 month ago

Pls . Can u repeat Second again but more easier

Ebrahim Hemaid - 7 years, 5 months ago

nice work it helped me understand

madison hofacker-haley - 7 years, 5 months ago

Similarly with augmentic matrix, add first equation to the negative of second, then that equation the original third equation, result two x eq fourteen x eq seven use new eq and subtract it from original third eq , z eq seventeen, subtract new eq from original second eq conseyenly y eq three

Yuliya Skripchenko - 7 years, 5 months ago
Muhammad Jamil
Dec 25, 2013

(x+y) +(y+z) +(z+x) =10+20+24 2(x+y+z)=54 x+y+z= 54/2 x+y+z=27

Good

Jenny Penn - 7 years, 4 months ago

add all three formulas we get, 2x+2y+2z=54 taking 2 common we get x+y+z=54/2 Ans=27

Bharath Bhat
Feb 1, 2014

x + y=10, y+z=20, z+x=24 add the three equations 2(x + y+ z)=54 x+y+z=27

x+y =10 -------(1) y+z = 20 -------(2) z+x = 24 -------(3)

From eqn (1) => x = 10 -y ------(4)

Replacing x in eqn (3) z+(10-y) = 24 z-y = 14 ---------(5)

Adding eqn (2) & (5) gives => 2z=34 which implies z = 17

Replace z in eqn (2) to find y value => y = 20-17 = 3

Replace y value in eqn (4) to find x value => x = 10-3 = 7

Hence the values of x,y,z are 7,3,17 So the answer to the given question (x+y+z) is 27

Luisa Rossetto
Jan 28, 2014

This is an easy one...

x = 10 - y

z + 10 - y = 24

z = 14 + y

y + 14 + y = 20

y = 3

z = 14 + 3 = 17

x = 10 - 3 = 7

x + y + z = 7 + 3 + 17 = 27

Upen Mishra
Jan 28, 2014

adding all these x+y+y+z+z+x=10+20+24 2(x+y+z)=54 x+y+z=54/2 x+y+z=27

Lucky Khan
Jan 27, 2014

using equ:1&3 i.e. (x+y = 10) - (z+x = 24) which gives, y-z = -14 adding this to equation (2) y-z = -14 + y+z =20 which gives 2y = 6 so y=3 , now adding y=3 to equ: 3 x=y=z = 24+3 = 27

Shaukat Khan
Jan 24, 2014

simply x+y+z=27

Chris Lee
Jan 24, 2014

Pick any equation out of 3, ie: I picked 2nd: y + z = 20. So I need to know the equation of y and z, which can be obtained from the question it self:

y = 10 - x

z = 24 - x

Hence:

   (10 -x) + (24 - x) = 20                                                                                                                                                                                             
   x = 7

So,
x + (y + z) = 7 + 20 = 27

Sam Helfgott
Jan 23, 2014

7 + 3 = 10 3 + 17 = 20 17 + 7 = 24 so x = 7 y = 3 z = 17 x + y + z = 27

Anas Moiz Hashmi
Jan 23, 2014

Add all three equations we get: 2x+2y+2z=10+20+24

After solving we get: x+y+z=27

take y+z = 20 ===> z = 20 - y,,, substitute the value z in z+x = 24 ====> 20 - y + x = 24===>x - y = 4,,, solve x + y = 10 and x - y = 4 ====> x = 7,,, substitute the value 7 in first equation ==> x+y = ,24 ===>y = 3,,, put y value in second equation ===>z = 17... x+y+z = 7+3+17=27.

Eshita Ghosh
Jan 22, 2014

-->(x+y)+(y+z)+(z+x)=10+20+24 -->2x+2y+2z=54 -->x+y+z=27 Ans: 27.

Akhil Akhi
Jan 21, 2014

by adding x+y+y+z+z+x=54,2x+2y+2z=54,x+y+z=27.

Adding all three equation we get, (x + y) + (y + z) + (z + x) = 10 + 20 + 24 or, 2( x + y + z) = 54, Therefore (x + y + z) = 54/2 = 27

Arjun Rana
Jan 21, 2014

step1:- x=10-y, y+z=20, z+(10-y)=24;

step2:- x=10-y, y+z=20, z=14+y;

step3: x=10-y, 2y+14=20, z=14+y;

step4:- x=10-y, y=3, z=14+y;

step5:- x=7, y=3, z=17; ans:- x+y+z=27

Mansi Khatri
Jan 21, 2014

x + y + y + z + z + x = 54. Then, 2 (x+y+z) = 54, and 54/2 = 27 Ans

Celinmariya P.N
Jan 20, 2014

x+y+y+z+z+x=10+20+24= 2x+2y+2z=54= 2(x+y+z)=54= x+y+z=54/2=27

Solution: X+Y=10…….(1) Y+Z=20………(2) Z+X=24………(3) Now, (1)+(2) Z+X+2Y=30 =>24+2Y=30 [From eqn. (3) ] So, Y=3 X=7 And Z=17 Now, X+Y+Z=27

When we add x + y x+y to y + z y+z we get x + 2 y + z = 30 x+2y+z = 30 . Now x + z = 30 2 y x+z=30-2y . But we know that x + z = 24 x+z=24 therefore we equate 30 2 y 30-2y with 24 and we get y = 3 y=3 . With this information we can find the value of x and later the value of z. The answer is 27

Saranya Gopinath
Jan 17, 2014

adding three equations we have,

2x + 2y + 2z = 54

or 2(x+y+z) = 54

or x + y + z = 27

Adding the three equations we get 2(x+y+z)=24+10+20 = 54 Therefore x+y+z=54/2 = 27 Ans. 27

Govind Kalaga
Jan 17, 2014

solve the equations for x,y, and z and find the result as27

Sandeep Sharma
Jan 16, 2014

x+y=10....(7,3) y+z=20....(3,17) z+x=24...(17,7) hence...x+y+z=24

Zare Ahmer
Jan 15, 2014

Add all of equation

x+y+y+z+z+x =10 +20 +24

2x+2y+2z =54

taking 2 as Common

2(x+y+z)=54

Divide 2 on b/s

x+y+z=27;

Sowmy Vivek
Jan 15, 2014

by solving v get x=7 y=3 z=17 soo x+y+z=27

Patne Shivakumar
Jan 13, 2014

from x+y=10 y=10-x this in eq 2 we get 10-x+z=20 now from eq 3 z=24-x now 10-x+24-x=20 so x=7 substitute value of x in other eq we get y=3 & z=17 so........... x+y+z=27

Aadya Rathi
Jan 13, 2014

X+Y+Y +Z +Z+X = 10+20+24 2(X+Y+Z) = 54 X+Y+Z=54/2 X+Y+Z =27

Jonas Corvera
Jan 11, 2014

5+10+12=27

Shivani Agrawal
Jan 11, 2014

there in first equation x+y=10 so y=10-x.....if we put this value of y in second equation at the place of y then we get 10-x+z=20 .then z=10+x..then put this value of z in third equation then we get x=7...then put this value in first equation then we get y=3 ....after tht we get z=17..then x+y+z=27...

Mahmoud Hesham
Jan 11, 2014

x+y+y+z+z+x=24+20+10 \ 2x+2y+2z+54 divide all with 2 \ x+w+z=27

Asad Raza
Jan 11, 2014

Just add above three equations you will get 2x+2y+2z = 10+20+24 => 2(x+y+z) = 54 => x+y+z = 54/2 => x+y+z = 27

Bushra Ali
Jan 11, 2014

x+y =10 ........ y+z=20 ....... z+x=24 ..... adding 3 equations we get ...... x+y+y+z+z+x=10+20+24 ...... 2x+2y+2z=54 ,,,,, 2(x+y+z) =54 .... x+y+z=54/2 ... x+y+z=27

Sandeep Kumar
Jan 11, 2014

x= 3 y= 7

z= 17

answer: x + y + z = 27

Srinivas Y
Jan 10, 2014

x+y-y+z=10-20;
x-z=-10:
x-z+z+x=-10+24:
x=7:
y=3:
z=17:
7+3+17=27:





Neil Jake Doria
Jan 10, 2014

x+y=10 y+z=20 z+x= 24 5+5=10 10+10=20 12+12 = 24

x+y+z = 27 5+10+12=27

Piyush Goyal
Jan 10, 2014

as x+y = 10 ,y=z =20 , z+x = 24 BY adding all the three equation we get 2x+2y+2z =54 by taking 2 as common we get 2(x+y+z) = 54 this implies, x+y+z= 27

Loza Elabd
Jan 9, 2014

Y+Z=20 *-1 =(-Y-Z=-20) +(Z+X=24)= (X-Y=4) +(X+Y=10)=2X=14 (X=7) (Y=3) ( Z=17) ( X+Y+Z)=7+3+17=24

Dube Ashish
Jan 8, 2014

adding all the three equations we get.. x+y+y+z+z+x=10+20+24

2x+2y+2z=54

we get 2(x+y+z)=54

x+y+z=27

Sakar Koot
Jan 8, 2014

x+y=10 y+z=20 x+z=24

                       x+y+y+z+x+z=10+20+24
                                2(x+y+z)=54

                                  x+y+z=27
Zainab Fatima
Jan 8, 2014

add all these three equations we get 2x+2y+2z=54
2(x+y+z)=54 x+y+z=27

Ahmed Arshad
Jan 8, 2014

x+y=10 y+z=20 z+x=24

x=10-y z=24-10+y z-y=14 z+y=20 2z=34 z=17 x=7 y=3 x+y+z=7+3+17=27

Nitish Mittal
Jan 8, 2014

x+y+y+z+z+x=10+20+24 2x+2y+2z=54 2(x+y+z)=54 x+y+z=54/2 =27

Jok3r Dude
Jan 7, 2014

We just add x+y, y+z and z+x, Like x+y+y+z+z+x=10+20+24 We get 2x+2y+2z=54 Taking 2 common- 2(x+y+z)=54 Dividing 54/2 we get 27 so, x+y+z=27 Cheers!

Xavier Vowles
Jan 6, 2014

If all the equations are added up, you can see than 2x + 2y + 2z = 10 + 20 +24 And thus divide both sides by two, and you get 27.

Ikram Ullah
Jan 6, 2014

X+Y+Y+Z+Z+X=10+20+24 2X+2Y+2Z =54 2(X+Y+Z)=54 X+Y+Z=54/2 X+Y+Z=27

Harpreet Singh
Jan 6, 2014

2(x+y+Z)=20+10+24 x+y+Z=54/2 =27

Bikash Jena
Jan 6, 2014

Here, x + y = 10 (...1)

y + z = 20 (...2)

z + x = 24 (...3)

Adding (...1), (...2) and (...3), we get,

(x + x) + (y + y) + (z + z) = 54

2(x + y +z) = 54

x + y + z = \frac {54}{2}

x + y + z = 27

Norhan Wael
Jan 6, 2014
  • x+y=10 (x in terms of y) x= 10-y *y+z=20 (z in terms of x) z=20-y *z+x=24 substitute by y 20-y+10-y=24 20+10-24=2y divide by 2 y=3 Then x=7 and z=17 *x+y+z= 3+7+17=27
Atul Kaushik
Jan 6, 2014

x+y+y+z+z+x=10+20+24 2x+2y+2z=54 2(x+y+z)=54 x+y+z=27

Abhishek Sanghai
Jan 5, 2014

add all equations...... now u will see the pattern..

I solved this problem replacing the unknowns in the equations. So, if x + y = 10, y = 10 - x. So, if 10 - x + z = 20, z = 20 - 10 + x. Replacing in the last equation, 20 -10 + x + x = 24. Solving, 2x = 14, and x = 7. Replacing again, y = 10 - 7, so y = 3 and z = 10 + 7, so z = 17. Finishing, x + y + z = 7 + 3 + 17 = 27.

Joy Emmanuel
Jan 5, 2014

First you need to find out what x is by check through each number added to another number makes ten the see if it works for the other equations.

Anil Chik
Jan 5, 2014

its very easy..... X+Y=10------------(1) Y+Z=20------------(2) Z+X=24------------(3) add three equations then we get 2(X+Y+Z)=54 implies X+Y+Z=27

x+y+0z=10 eq(1) 0x+y+z=20 eq(2) x+0y+z=24 eq(3) from eq 1 and 2 x-z=-10 eq(4) and from eq 3 and 4 x=7 x+z=24, 7+z=24. z=24-7=17 and eq(1) x+y=10 7+y=10, y=10-7=3

Numan Shah
Jan 5, 2014

x+y+y+z+x=10+20+24 2x+2y+2z=54 2(x+y+z)=54 (Dividing both side by 2) x+y+z=27

Satyajit Maity
Jan 5, 2014

just sum the three equations & then we get 2( x+y+z) = 54 and it implies that x+y+z = 27.

Sarath Cp
Jan 4, 2014

( x + y ) + ( y + z ) + ( z + x ) = 10 + 20 + 24 (x + y ) + (y + z) + (z + x) = 10 + 20 + 24

Then 2 ( x + y + z ) = 54 2( x + y + z ) = 54

x + y + z = 27 x + y + z = 27

Katrina Touchet
Jan 4, 2014

x+y=10

solve for y

y=10-x

(10-x)+z=20

solve for z

z=10+x

(10+x)+x=24

solve for x

x=7

y=10-7=3

z=10+7=17

Shweta Verma
Jan 4, 2014

x + y=10 z + x=24 =) x=10 - y --------(1) =) z=24-x-------------(2)

Put value of x nd z in y+z=20 we get 10-y+24-y=20 =) y= 3

put value of y in (1) nd (2) we get x= 7 nd z=17

good but little bit time taken.

seetharam patnaik - 7 years, 5 months ago
Luiz Simas
Jan 4, 2014

Very easy!

Just sum the 3 lines and find 2x+2y+2z = 54. So, X + Y + Z = 54/2 = 27.

Muhammad Tariq
Jan 4, 2014
  1. (x+y)+(y+z)+(z+x)=10+20+24
  2. 2x+2y+2z=54
  3. 2(x+y+z)=54
  4. x+y+z=54/2
  5. thus, x+y+z=27!
Charlene Antonio
Jan 4, 2014

equation (1): x + y = 10 >>> y = 10 - x equation (1.1) equation (3): z + x = 24 >>> z = 24 - x equation (3.1) equation (2): y + z = 20 >>> substitute the value of y and z from equation (1.1 and 3.1) so, (10 - x) + (24 - x) = 20 >>> -2x + 34 = 20 >>>-2x = -14 >>> x = 7 using x = 7, find y and z equation (1) x + y = 10 >>> y = 10 - 7 >>> y = 3 equation (3) z + x = 24 >>> z = 24 - 7 >>> z = 14

x + y + z = 7 + 3 + 17 = 27

Aman Malhotra
Jan 4, 2014

x+y+y+z+z+x=10+20+24 2x+2y+2z=54 2(x+y+z)=54 x+y+z=54/2 x+y+z=27

Hafiz Irfan
Jan 4, 2014

x=7, y=3 & z=17

Noor Ali
Jan 3, 2014

get z's values from last 2 given equations ; compare both and then put in required equation , x's value which you got and y+z is given then we solve our problem by getting answer 27.

Mohamed Jalloh
Jan 3, 2014

x=7,y=3, and z=17
7+3+17=27

Lakshmi Tumati
Jan 3, 2014

First you figure out the different possibilities for x+y=10. Then, you figure out the different possibilities for y+z=20. After that, you see which pair has the same number for y. That means you know what x and z are because they are part of the first two equations and you already know what y is. You can check it over by doing the last equation and seeing if it is correct. You get x=7, y=3, and z=17. When you add them all together you get 27.

Roopa Jayasimha
Jan 3, 2014

Adding we get x+y+y+z+z+x=10+20+24=54 2(x+y+z)=54 x+y+z = 54/2 = 27

Hassan Alsamahi
Jan 3, 2014

x + y = 10 hence : y = 10 - x y + z = 20 hence : 10- x + z = 20 hence : z = 20 - 10 + x hence: z = 10 + x z + x = 24 hence : (10+x) + x = 24 hence : 10 + 2x = 24 hence : 2x = 14 x = 7 y = 3 z = 17 x + y +z = 7+3+17 = 27

Luke Limbo
Jan 2, 2014

I use the trial and error method. And I get X=7 Y=3 Z=17

Isaac Jacobs
Jan 1, 2014

First, take two of the three equations, x+y=10 and x+z=24. Using elimination, we end up with z-y=14. Now, take the untouched equation, z+y=20, and use elimination with the new equation. We end up with z=17. After plugging in z, we can find x and y, which are 7 and 3, respectively. Add 17, 7, and 3 to get an answer of 27.

Adding x+y,y+z and z+x, we get

x+y+y+z+z+x = 10+20+24

2(x+y+z) = 54

x+y+z = 54/2

x+y+z = 27

Avanimitra Chilla
Dec 31, 2013

x+y=10 and y+z=20 solve these two equations linearly and find x-z and then solve those two equations then you get the final answer as 27

Sudarshan Pune
Dec 30, 2013

Add all the equation: 2(x+y+z) = 10+20+24 ; 2(x+y+z) = 54 ; x+y+z = 54/2 ; x+y+z = 27

2(x+y+z)=54 x+y+z = 27

Unnati Bindal
Dec 28, 2013

FIRST OF ALL.. AS.. (x+y)+(y+z)+(z+x)=10+20+24=54 now, we will open the brackets and then solve this question as an equation. x+y+y+z+z+x=54 this implies that 2x+2y+2z=54 now as 2 is common: so we will take 2 outside the bracket.. 2(x+y+z)=54 now we will follow the rule of transposition.. this implies that(x+y+z)=54/2=27...

add 3 equations, we get 2(x+y+z)= 54.so x+y+z= 27

Dal Mushtaq
Dec 27, 2013

(x+y)+(y+z)+(z+x)=10+20+24 x+y+y+z+z+x=54 2x+2y+2z=54 take 2 as common 2(x+y+z)=54 2/2(x+y+z)=54/2 x+y+z=27

Ayudhia Wijaya
Dec 27, 2013

2(x+y+z)=54 so, x+y+z=27

Abdulahad Pasha
Dec 27, 2013

x + y =10...(1) y + z =20...(2) z + x =24...(3) x + y + z =?? ...(4)

Add eq.(2) and eq.(3) x + y + 2z = 44 from eq.(1) we know that x+y=10 10 + 2z = 44 2z = 34 z = 17. Put x+y=10 and z=17 in eq.(4) x+y+z = 10+17 = 27.

but x=4 y=6 z=20

Mahmoud Elentably - 7 years, 5 months ago

x+y+y+z+z+x=10+20+24 x+y+z=27

Sayeda Sultana
Dec 26, 2013

x+y+y+z+z+x=10+20+24 2(x+y+z)=54 x+y+z=27

Fadlan Rico
Dec 26, 2013

x+y+y+z+x+z=10+20+24 2x+2y+2z=54 2(x+y+z)=54 x+y+z=27

Badr Abaza
Dec 26, 2013

Q : x+y=10 A : 7+3=10

Q : Y+Z=20 A : 3+ 17=20

Q : Z+X=24 A : 17+7=24

To add the values : x+y+z :
7+3+17= 27

Sachin Gaur
Dec 26, 2013

by adding these 3 equations

x+y+y+z+z+x=10+20+24

2x+2y+2z=54

2(x+y+z)=54

(x+y+z)=(54/2)

(x+y+z)=27

Sarfaraz Ali
Dec 26, 2013

x +y = 10 (i) y + z = 20 (ii) z + x = 24 (iii)

subt i from ii we get z - x = 10 add this to iii we get z = 17 put z = 17 in ii and iii we get y = 3 and x= 7 then x + y +z = 7 + 3 + 17 = 27

Nishanth Krishh
Dec 26, 2013

Add all 3 equations, then you get 2(x+y+z)=54; then x+y+z=54/2=27.

2x+2y+2z=54. x+y+z=27

Elton Jay Pasco
Dec 26, 2013

x+y=10
y+z=20
z+x=24
so


find the value of x
x+y=10 ------> x=10-y
convert it to the third equation because in the second equation there is no x
z+x=24 ------> z+10-y=24 find the value of z so that we can use it to the second equation so z=14+y
convert now the value of z to the second equation
y+z=20 ----> y+14+y=20 ----combine like terms----> 2y=6 where y=3
use the value of y to get x and z
until you find the answer where x=7 , y=3 , z=17 so x+y+z=27 ('_')






Amrit Kaur
Dec 25, 2013

X =10-Y , Y=20-Z , Z=24-X ,

YOU NEED TO MAKE SURE THERE IS ONLY ONLY 1 UNKNOWN.I CHOOSE Z TO BE THE UNKNOWN BY CHOOSING AN EQUATION AMONG THE 3 EQUATIONS TO SUBSTITUTE OTHER DERIVED EQUATIONS TO MAKE SURE THERES ONLY ONE UNKNOWN, Z.

I CHOSE EQUATION X=10 - Y TO SUBTITUTE OTHER EQUATIONS

Z=24-X IS MODIFIED TO X=24-Z

NEXT SUSTITUTE THE EQUATIONS

24-Z=10-(20-Z) , Z=17 , Y=20-Z , y=3 , x=10-y , x=7 , x+y+z=7+3+17 , X+Y+Z=27

Harshal Soni
Dec 25, 2013

Adding all the 3 we get 2(x+y+z)=54 so x+y+z=27

x+y+y+z+z+x=10+20+24 2x+2y+2z=54 then, divide both sides by 2 x+y+z=27

Souvik Mukherjee
Dec 25, 2013

(y+z) - (x +y)= (z-x); (z+x) +(z-x) gives d value of z. putting z in 2nd eq. solves y and samely replacing y's in 1st eq gives x. all of the variables can be added then.

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