SOLUTION: Please help me to solve this problem. Given that (x + y)*2=63 and xy=65, find the value of x*2 + y*2 - 1. Thank you...

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Please help me to solve this problem. Given that (x + y)*2=63 and xy=65, find the value of x*2 + y*2 - 1. Thank you...       Log On


   

Question 882141: Please help me to solve this problem. Given that (x + y)*2=63 and xy=65, find the value of x*2 + y*2 - 1. Thank you...
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
Question almost looks like a rectangle problem.

You want x and y solutions.
2x%2B2y=63
y=%2863-2x%29%2F2
-
Substitute.
x%2863-2x%29%2F2=65
x%2863-2x%29=130
-2x%5E2%2B63x-130=0
2x%5E2-63x%2B130=0
D=(63)^2-4*2*130=3969-1040=2929=101*29
highlight%28x=%2863%2B-+sqrt%282929%29%29%2F%282%2A2%29%29
The results for x will be positive either way, so you might expect y to be the other value; the PLUS form is one dimension and the MINUS form is the other dimension.

You can finish from that.