先化简再求值2(x+5)(x
2(x+5)(x-4)-3(x-6)(x+1)，其中x=2
2(x+5)(x-4)-3(x-6)(x+1)，其中x=2 2(x+5)(x-4)-3(x-6)(x+1) =2*(x^2+x-20)-3*(x^2-5x-6) =2x^2+2x-40-3x^2+15x+18 =-x^2+17x-22 =-2^2+17*2-22=-4+34-22=8