Question

若f(x)=(3x-2)^5-8(3x-2)^4+6(3x-2)^3+3(3x-2)^2+29(3x-2)+20,试求f

Answer 1

a=3x-2=7

a^5-8a^4+6a^3+3a^2+29a+20

=a^4(a-8)+6a^3+3a^2+29a+20

=-a^4+6a^3+3a^2+29a+20

=a^3(-a+6)+3a^2+29a+20

=-a^3+3a^2+29a+20

=a^2(-a+3)+29a+20

=-4a^2+29a+20

=a(-4a+29)+20

=a+20

=27