Question

(x-2)+x的2方(2-x),3a(x-y)+9(y-x),(2m-3n)的2方-（2m-3n)

Answer 1

(x-2)+x^2(2-x)

=(x-2)-x^2(x-2)

=(x-2)(1-x^2)

=(x-2)(x+1)(x-1）

3a(x-y)+9(y-x)

=3a(x-y)-9(x-y)

=3(x-y)(a-3)

(2m-3n)^2-(2m-3n)

=(2m-3n)(2m-3n-1)