Question

Simplify: $3$ ${}^3\sqrt{40}$ - $4$ ${}^3\sqrt{320}$

Answer 1

For this we must know how to find out the cube root of a number.

We need to simply $[3\times (40{)}^{\frac{1}{3}}]-[4\times \left(320{)}^{\frac{1}{3}}\right]$

$(40{)}^{\frac{1}{3}}=[2\times \left(5{)}^{\frac{1}{3}}\right]$

$(320{)}^{\frac{1}{3}}=[4\times \left(5{)}^{\frac{1}{3}}\right]$

Therefore the equation becomes

$[3\times 2\times (5{)}^{\frac{1}{3}}]-[4\times 4\times \left(5{)}^{\frac{1}{3}}\right]=[-10\times (5{)}^{\frac{1}{3}}]$