计算:1.(-2x-7y)^22.(-4x-3y)(4x-3y)3.(-1/2a+2b)(1/2a-2b)4.(a/3+3)^2+(a/3-3)^25.(-x-y-1)(x-y-1)
简便运算
1.103×97-104^2
2.2012^2-2013×2011
富宇回答:
1.(-2x-7y)^2=4x²+28xy+49y²2.(-4x-3y)(4x-3y)=9y²-16x²3.(-1/2a+2b)(1/2a-2b)=-(1/2a-2b)²=-1/4a²+2ab-4b²4.(a/3+3)^2+(a/3-3)^2=a²/9+2a+9+a²/9-2a+9=2a²...