計算: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) 簡便運算 1.103×97-104^2 2.2012^2-2013×2011

計算: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) 簡便運算 1.103×97-104^2 2.2012^2-2013×2011

1.(-2x-7y)^2 =4x²;+28xy+49y²;2.(-4x-3y)(4x-3y)=9y²;-16x²;3.(-1/2a+2b)(1/2a-2b)=-(1/2a-2b)²;=-1/4a²;+2ab-4b²;4.(a/3+3)^2+(a/3-3)^2 =a²;/9+2a+9+a²;/9-2a+9=2a²…