(2)5x(x2+2x +1) - 3(2x + 3)(x - 5)

问题描述:

(2)5x(x2+2x +1) - 3(2x + 3)(x - 5)

=5x^3+10x^2+5x-3(2x^2-10x+3x-15)
=5x^3+10x^2+5x-3(2x^2-7x-15)
=5x^3+10x^2+5x-6x^2+21x+45
=5x^3+4x^2+26x+45