[tex](x+y)^4=x^4+y^4[/tex] We know this is true if x and/or y = 0, but what other possibilities are there? I solved for (x+y)^2=x^2+y^2, which has x=-y as a possibility. The solution isn't necessary, a couple tips should lead me in the right direction. I broke it down in several ways, but a hint for something to look for would be great. I happen to always be stuck with something along the line like... STUFF+x^2y^2 I can get the stuff area to equal to zero, but because the are both odd or even numbers that are equal I am always stuff with the odd one at the end. I lost my paper that shows what STUFF is (stupid I know), but I'll work out a second time and maybe then I'll find a solution. Any advice would be great. Thanks.