Question

七年级 下册

(m+2n)(m-2n)=
(2n+5)(n-3)=
(x+2y)^2=
(ax+b)(cx+d)=
(x+y)(a+2b)=
(2a+3)(3/2b+5)=
(2x+3)(-x-1)=
(-2m-1)(3m-2)=
(x+y)^2=
(-2x+3)^2=
要过程。

Answer 1

(m+2n)(m-2n)=m的平方-（2n）的平方=m的平方-4n的平方

（2n+5)(n-3)=2n*n-2n*3+5n-15