整式的几道练习[(2(a-b)的3次方][-3(a-b)的2次方][-2/3(a-b)]x^n-1(2x的n次方-4x的n+1次方+5x的n+3次方）（-a-3ab)(-3ab+a)

Answer 1

[2(a-b)]³[-3(a-b)]²[-2/3(a-b)]
=-8(a-b)³*9(a-b)²*2/3(a-b)
=-48(a-b)^6
x^(n-1)[2x^n-4x^(n+1)+5x^(n+3)]
=2x^(2n-1)-4x^(2n)+5x^(2n+2)
(-a-3ab)(-3ab+a)
=(-3ab)²-a²
=9a²b²-a²