Question

Find the value of using the short-cut method:
(84)³

Answer 1

${\left(84\right)}^3$

Here, a = 8 and b = 4

Using the formula $a^3+3a^{2}b+3a{b}^2+b^3$:

64 $\times$ 8	64 $\times$ 12	16 $\times$ 24	16 $\times$ 4
512 $+$ 80	768 $+$ 39	384 $+$ 6	64
592	807	390

∴ ${\left(84\right)}^3$ = 592704