If b + c = 1 5 and a − d = 4 , what is the value of
a b − c d + a c − b d ?
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ab - cd + ac -bd = a(b+c) - d(c+b) = (b+c) (a-d) = 15*4 = 60
that's strange... in my version the 15 is displayed as a 1.
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in my version too 15 is displayed as 1.
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that`s true Ankit Chauhan.its displayed as 1 in my version tooo
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@Sanju Meghana Sangers – Thanks. I have updated the answer/problem accordingly.
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Tks! I just know to do using values.
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ab-cd+ac-bd = ab+ac-cd-bd = a(b+c)-d(c+b) = a(b+c)-d(b+c) = (b+c)(a-d) = 15X4 = 60
ab-cd+ac-bd or, ab-bd+ac-cd or, b(a-d)+c(a-d) or, (b+c)(a-d) or, 15*4 [this value is given] so, 60 (ANS)
ri8
ab-cd+ac-bd then it is equal to a(b+c)-d(b+c) by taking common =(b+c)(a-d) =15 * 4 [ given that b+c = 15 & a-d = 4] =60 [solved]
Rearranging the terms so that it is easier to factorise the equation, a b − c d + a c − b d = a b + a c − b d − c d = a ( b + c ) − d ( b + c ) = ( a − d ) ( b + c ) Now substituting b + c = 1 5 and a − d = 4 gives: ( a − d ) ( b + c ) = ( 4 ) ( 1 5 ) = 6 0 Therefore, the answer is 60 .
(ac-cd)+(ab-bd)=c(a-d)+b(a-d)=(c 4)+(b 4)=4(c+b)=4*15=60
b+c=15. a-d=4. (b+c)(a-d)=15*4. ab-db+ac-dc=60. simple!!
from given we can assume a=4+d;b=15-c substitute in ab-cd+ac-bd v will get 60
ab+ac-cd-bd=a(b+c)-d(b+c)=(a-d)(b+c)=4 * 15=60
Given that, b + c = 1 5 ....(i) and a − d = 4 ....(ii)
Multiplying (i) and (ii), we get,
( b + c ) ( a − d ) = 1 5 × 4
⟹ a b − b d + a c − c d = 6 0 ⟹ a b − c d + a c − b d = 6 0
ab - cd + ac - bd = a(b + c) -d(b + c) = (a - d)(b + c) = 15 x 4 = 60
ab-bd+ac-cd = b(a-d) + c(a-d) =(a-d)(b+c) =(4)(15) =4x15 =60
ab - bd + ac - cd = b(a-d) + c(a-d) = (b+c)(a-d) = 15 x 4 = 60. ANSWER :60
b+c =15 a-d = 4 ab-cd+ac-bd or a(b+c)-d(b+c) (a-d)(b+c) = 15 x 4 = 60
ab+ac-bd-cd = a(b+c)d(b+c)
= (b+c)(a-d)
= (15)(4)
=60
(ab-bd) +(ac-cd)= b(a-d)+c(a-d) ,a-d=4 @ 4b+4c=4(b+c)=4x15=60
(b+c).(a-d) = ab-cd+ac-bd= 15x4=60
ab-cd+ac-bd =ab+ac-bd-cd =a(b+c)-d(b+c)=(b+c)(a-d)=15*4=60 [as b+c=15; a-d=4]
(b+c) * (a-d) = 15*4
ba-bd+ac-dc = 60
ab-cd+ac-bd = 60.
Hence prooved
ab-cd+ac-bd= (b+c)(a-d)=15*4=60
ab-cd+ac-bd=ab+ac-(bd+cd)=a(b+c)-d(b+c)=(b+c)(a-d)=15*4=60
a(b+c)-d(b+c); (b+c)(a-d)=15*4=60.
(b+c)(a-d) = (15)(4) ab-cd+ac-bd= 60
(b+c)(a-d)=15*4 ab-cd+ac-bd=60
ab-cd +ac -bd given: b+c = 15 and a - d = 4........ first re-arrange the given equation in the form => ab + ac - bd - cd => a(b + c) - d(b + c) .....(eqn 1) put the value in the eqn......1 => a . 15 - d . 15 => 15 (a - d) => 15 . 4 => 60 ans...
We Have b+c=15 And a-d=4...Simply Multiply Both Equations (b+c)(a-d)=15 Times 4=60
ab-cd+ac-bd = a(b+c)-d(b+c)=(a-d)(b+c)=15\times 4 = 60
a(b+c) - d(b+c) =(a-d)(b+c) sub in the statement: b+c=15, a-d=4; =4(15) =60
a(b+c)-(b+c)d =a(15)-(15)d =15(a-d) =15(4) =60
ab-cd+ac-bd =a(b+c)-d(b+c) =(a-d)(b+c) =4*15= 60
We can rearrange the equation to a b + a c − c d − b d . Then we factor out the a and d to get a ( b + c ) − d ( b + c ) . That is the same as ( a − d ) + ( b + c ) We can replace the with the values of b + c and a − d to get 1 5 ∗ 4 , which is 6 0
a(b + c)- d(b + c) => (a - d) . (b + c) = 15 . 4 = 60; please check yours, you have done incorrect.
ab + ac - cd -bd = a(b + c) -d(b + c) = (b + c) (a - d) =(15)(4) = 60
Multiplying (a-d) (b+c)=15 4 ab-ac-bd-cd=60
Therefore ab-cd+ac-bd=60
(b+c)x(a-d)=ab-cd+ac-bd 15x4=60
By multiplying the two equations together and expanding, we get a b − c d + a c − b d = 6 0 .
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a b − c d + a c − b d factors into ( a − d ) ( b + c ) . Using substitution, we get ( a − d ) ( b + c ) = 4 ⋅ 1 5 = 6 0 .