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1. I'm stuck on this:
Given that x − y = 8, and that xy ≤ 240, find the maximum value of (x + y).
2. (Original post by dimapos32)
Since x - y = 8, x = 8 + y.

xy ≤ 240
(y+8)y ≤ 240
y^2 + 8y - 240 ≤ 0

y = [ -20 , 12 ]
max value of y = 12 --> x = 20

So the maximum value is 32 ( x + y = 20 + 12 = 32 )
so what is the maximum value exactly??Could you explain please?
3. (Original post by Chelsea12345)
so what is the maximum value exactly??Could you explain please?
(Original post by dimapos32)
So the maximum value is 32 ( x + y = 20 + 12 = 32 )
4. (Original post by dimapos32)
Thankyou!

Updated: November 14, 2016
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