(1)3(a+b)^2+6(a+b) (2)m(a-b)-n(a-b) (3)6(x-y)^3-3y(y-x)^2 (4)mn(m-n)-m(n-m)^2
问题描述:
(1)3(a+b)^2+6(a+b) (2)m(a-b)-n(a-b) (3)6(x-y)^3-3y(y-x)^2 (4)mn(m-n)-m(n-m)^2
答
(1)3(a+b)^2+6(a+b)
=3(a+b) (a+b+2)
(2)m(a-b)-n(a-b)
=(a-b)(m-n)
(3)6(x-y)^3-3y(y-x)^2
=6(x-y)^3-3y(x-y)^2
=3(x-y)^2(2x-2y-3y)
=3(x-y)^2(2x-5y)
(4)mn(m-n)-m(n-m)^2
=mn(m-n)-m(m-n)^2
=m(m-n)(n-m+n)
=m(m-n)(2n-m)