Question

$8 {}^{ \frac{2}{3} } \times a - \sqrt[3]{( - 8) {}^{ - 2} }$

Answer 1

$8^{ \frac{2}{3} } \times a - \sqrt[3]{( - 8)^{ - 2} } =$

$(2^3)^{ \frac{2}{3} } \times a - \sqrt[3]{\left(-2^3\right)^{-2} } =$

$2^2 \times a - \sqrt[3]{\left(-2\right)^{-6} } =$

$4\times a -(\left(-2\right)^{-6})^{ \frac{1}{3} } =$

$4\times a -\left(-2\right)^{-2})=$

$4\times a -\left(- \frac{1}{2} \right)^{2}=$

$4\times a -\frac{1}{4}$