Cancel out $\dfrac{a\left(a-b^{\frac12}\right)}{a+a^{\frac12}\cdot b^{\frac14}}$ [duplicate]
Cancel out $$\dfrac{2-54b}{2-6b^\frac13}$$ I really don't see what we are supposed to do. This is what I have tried to do with the numerator $$2-54b=2-9\cdot6b=2-3^3\cdot2b=2(1-3^3b)$$
Solution 1:
Let $x=3b^{1/3}$. Then $$\frac{2-54b}{2-6b^{1/3}}=\frac{1-x^3}{1-x}.$$
Using that $1-x^3=(1-x)(1+x+x^2)$, can you finish?