Question

求各位学霸帮忙解答，，有答必采纳

Answer 1

1、 原式=4［(X-Y)+2(X+Y)］［(X-Y)-2(X+Y)］
=-4(3X+Y)(X+3Y)
2、原式=X(X²-Y²)+Y(X²-Y²)
=(X+Y)²(X-Y)
3、原式=1/4(X-Y)²-(X-Y)+1
=1/4［(X-Y)-2］²
=1/4(X-Y-2)²。