计算:1.(-2x-7y)^2 2.(-4x-3y)(4x-3y) 3.(-1/2a+2b)(1/2a-2b) 4.(a/3+3)^2+(a/3-3)^2 5.(-x-y-1)(x-y-1)

问题描述:

计算:1.(-2x-7y)^2 2.(-4x-3y)(4x-3y) 3.(-1/2a+2b)(1/2a-2b) 4.(a/3+3)^2+(a/3-3)^2 5.(-x-y-1)(x-y-1)
简便运算
1.103×97-104^2
2.2012^2-2013×2011

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...