已知-m+2n=2,求5(m-2n)²+6n-3m-3的值

已知-m+2n=2,求5(m-2n)²+6n-3m-3的值
已知-m+2n=2,求5(m-2n)²+6n-3m-3的值

已知-m+2n=2,求5(m-2n)²+6n-3m-3的值
5(m-2n)²+6n-3m-3
=5[-(-m+2n)]²+3(-m+2n)-3
=5*(-2)²+3*2-3
=20+6-3
=23

原式=5（2n-m）^2+2(2n-m)-3
=5*4+2*2-3=21