Question

(a+b) whole power -3
${a + b}^{ - 3}$
​what is the formula of this

Answer 1

${(a + b)}^{ - 3} \\ = \frac{1}{ {(a + b)}^{3} } \\ = \frac{1}{ {a}^{3} + {b}^{3} + 3ab(a + b) }$

Tada!

Easy peasy.