(x+y)²-4(x+y-1)(x²+y²)²-4x²y²(x²+2x)²+2(x²+2x)+1a²-b²-2a+19-6a-6b+a²+2ab+b²
问题描述:
(x+y)²-4(x+y-1)
(x²+y²)²-4x²y²
(x²+2x)²+2(x²+2x)+1
a²-b²-2a+1
9-6a-6b+a²+2ab+b²
答
111111111
答
第一道=(x+y)²-4(x+y)+4=(x+y-2)²第2道=(x²+y²)²-(2xy)²=(x²+y²+2xy)*(x²+y²-2xy)=(x+y)²*(x-y)²第3道把x²+2x看成整体=(x²+2x+1)²第4...