Question

先化简,再求值：（3m-1）^2-3(2-5m+3m^2),其中m=-1/3

Answer 1

(m-1)^2-3(2-5m+3m^2)

=m^2-2m+1-6+15m-9m^2

=-8m^2+13m-5

=-(8m^2-13m+5)

=-(m-1)(8m-5) 将m=-1/3代入

=-92/9