Question

因式分解:-7(n-m)^3+14(m-n)^2-28(m-n)

Answer 1

-7(n-m)^3+14(m-n)^2-28(m-n)

=7(m-n)^3+14(m-n)^2-28(m-n)

=7(m-n)[(m-n)²+2(m-n)-4]

=7(m-n)(m-n+1+√5)(m-n+1-√5)