1.[ab(a^-ab)-a^b(a-b)]/(-3a^b^)

说明一下：我不会打立方,就用*代替一下
1.[ab(a^-ab)-a^b(a-b)]/(-3a^b^)
=[a^b-a^b^-a*b-a^b^]/(-3a^b^)
=0/(-3a^b^)
=0
2.8x^-(x-2)(3x+1)-2(x+1)(x-5）
=8x^-(x-2)(3x+1)-(2x+2)(x-5)
=8x^-3x^+x-6x+2-2x^+5x-2x+10
=3x^+13x+12