(x-2)(x-3)+2(x-5)(x+6)-3(x^2-7x+12)
问题描述:
(x-2)(x-3)+2(x-5)(x+6)-3(x^2-7x+12)
其中x=-5/2
答
(x-2)(x-3)+2(x-5)(x+6)-3(x^2-7x+12)
=x^2-5x+6+2x^2+2x-60-3x^2+21x-36
=18x-90
=18*(-5/2)-90
=-45-90
=-135