计算(1).(5x-2)(x-3)-(3x-1)(x-4)= (2).(x+3)(x²+9)(x-3)=

问题描述:

计算(1).(5x-2)(x-3)-(3x-1)(x-4)= (2).(x+3)(x²+9)(x-3)=

(5x-2)(x-3)-(3x-1)(x-4)
=5x^2-2x-15x+6-3x^2+x+12x-4
=2x^2-4x+2
(x+3)(x²+9)(x-3)
=(x^2-9)(x^2+9)
=x^4-81