几道初一下计算题

问题描述:

几道初一下计算题
①4(a-b)^2-(2a+b)(-b+2a)
②(x+y)^2*(x-y)^2
③(2x-3)(-2x-3)
④(3x+4y)^2

①4(a-b)²-(2a+b)(-b+2a)=4a²-8ab+4b²-(-2ab+4a²-b²+2ab)=5b²-8ab②(x+y)² ×(x-y)²=(x²+2xy+y²)(x²-2xy+y²)=x⁴-2x²y²+y⁴...