Question

计算：(a^2-b^2/b)^2÷(a^2+ab)^3×(ab/b-a)^2 通分：1-2x/3xy^2(x-3)与1-x/18y-2x^2y

初一同学的题目都没人懂么= =

Answer 1

[(a^2-b^2)/b]^2÷(a^2+ab)^3×[ab/(b-a)]^2
=(a^2-b^2)^2/b^2÷(a^2+ab)^3×a^2b^2 /(b-a)^2
=(a^2-b^2)^2/b^2×1/(a^2+ab)^3×a^2b^2 /(b-a)^2
=(a^2-b^2)^2×1/(a^2+ab)^3×a^2 /(b-a)^2
=[(a-b)(a+b)]^2×1/[a(a+b)]^3×a^2 /(b-a)^2
=(a-b)^2(a+b)^2×1/[a^3(a+b)^3]×a^2 /(a-b)^2
=(a+b)^2×1/[a^3(a+b)^3]×a^2
=1/a(a+b)

(1-2x)/[3xy^2(x-3)]
=2(1-2x)(x+3)/[6xy^2(x-3)(x+3)]

(1-x)/(18y-2x^2y)
=(1-x)/[2y(9-x^2)]
=-(1-x)/[2y(x^2-9)]
=-(1-x)/[2y(x-3)(x+3)]
=-3xy(1-x)/[6xy^2(x-3)(x+3)]