SOLUTION: If x+y=16 and xy=3, find the value of a) x^2 +y^2 b) (x-y)^2

Algebra ->  Equations -> SOLUTION: If x+y=16 and xy=3, find the value of a) x^2 +y^2 b) (x-y)^2      Log On


   

Question 1111095: If x+y=16 and xy=3, find the value of
a) x^2 +y^2
b) (x-y)^2
Found 2 solutions by ikleyn, josgarithmetic:
Answer by ikleyn(52814) About Me  (Show Source):
You can put this solution on YOUR website!
.
a)  x%5E2+%2B+y%5E2 = %28x%2By%29%5E2+-+2xy =  16%5E2+-+2%2A3 =  you calculate it.


b)  %28x-y%29%5E2 = %28x%2By%29%5E2+-+4xy = 16%5E2+-+4%2A3 = you calculate it.

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If you want to see other similar solved problems, look into the lesson

    - HOW TO evaluate expressions involving  %28x+%2B+1%2Fx%29,  %28x%5E2%2B1%2Fx%5E2%29,  %28x%5E3+%2B+1%2Fx%5E3%29  and  %28x%5E5%2B1%2Fx%5E5%29

in this site.


Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
%28x%2By%29%5E2=x%5E2%2B2xy%2By%5E2=16%5E2

x%5E2%2B2%2A3%2By%5E2=16%5E2
x%5E2%2By%5E2=16%5E2-6
highlight%28x%5E2%2By%5E2=250%29
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%28x-y%29%5E2
x%5E2-xy-xy%2By%5E2
x%5E2%2By%5E2-2xy
%28x%5E2%2By%5E2%29-2%2A3
250-6
highlight%28244=%28x-y%29%5E2%29