- #1
crakajackxx
Homework Statement
x and y are real numbers. prove that if x2-4x=y2-4y and x not equal to y, then x+y=4.
Homework Equations
n/a
The Attempt at a Solution
I tried using cases and making x and y positive and negative or even and odd, and that didnt work. then i tried completing the square on both sides and I got x=y.
please help~