Straight to the point
Given two numbers s and p such that s = 2 5 4 4 and p = 1 0 1 where x + y = p and x y = s , find x + y .
Inspired by chapter 1 in Mathematical Thinking by John P. D'Angelo and Douglas B. West.
The answer is 101.
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2 solutions
Can you please explain where I am going wrong?
x
+
y
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1
0
1
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x
y
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2
5
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4
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x
y
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5
0
8
8
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2
Adding
1
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2
x
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y
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2
x
y
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5
1
8
9
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x
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2
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5
1
8
9
x
+
y
=
7
2
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0
3
4
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Lol, x + y + 2 x y = ( x + y ) 2 , I didn't know that factorization.
I'm not sure whether you really confused yourself or you're just posting a bonus question. Anyway,
( x + y ) 2 = x 2 + y 2 + 2 x y
Your factorization is wrong.
If you're interested:
( x + y ) 2 = 1 0 2 0 1 x 2 + y 2 + 2 x y = 1 0 2 0 1 x 2 + y 2 = 1 0 2 0 1 − 2 ( 2 5 4 4 ) x 2 + y 2 = 5 1 1 3
Incredibly, just the 63% of people got this problem right.
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Well, some people see the question but never attempted. The percentage is affected by that too
I don't see where the problem is... It is given that x + y = p = 1 0 1 , so why do you ask for x + y ?
It's titled 'simple' because the answer is already given which causes some to overthink it. That and I wrote this post in little under 3 minutes without much thought.
I also think the same...It is given that x+y=101.And the question ask for same. LOL ;)
Umm, can you please explain my above doubt?
Given that x + y = p and p = 1 0 1
Therefore, x + y = 1 0 1
This question wins the honor of being the easiest question I have ever done on Brilliant