MathNet 2008-part-03 — 165 problems (EN–VI) Question 136

Express $(A-B)^{-1}$ in terms of $x$, if $A=\frac{3 x^{-\frac{1}{3}}}{x^{\frac{2}{3}}-2 x^{-\frac{1}{3}}}$ and $B=\frac{x^{\frac{1}{3}}}{x^{\frac{4}{3}}-x^{\frac{1}{3}}}$. Simplify the expression.