Question

(x-2)(x-3)+2(x+6)(x-5)-3(x²-7x+12),其中x=2.(先化简再求解)

Answer 1

原式=x²-5x+6+2（x²+x-30)-3x²+21x-36

=x²-5x+6+2x²+2x-60-3x²+21x-36

=18x-90

当x=2时

原式=18x-90=36-90= -54