Question

(m+2n)^2-6(m+2n)(2m-n)+9(n-2m)^2 因式分解

Answer 1

(m+2n)^2-6(m+2n)(2m-n)+9(n-2m)^2

=(m+2n)^2+6(m+2n)(n-2m)+[3(n-2m)]^2

=[(m+2n)+3(n-2m)]^2

=(5n-5m)^2

=25(n-m)^2