Question

EXPAND THIS = (21m - 15)³

Answer 1

$\huge{\red{heya\:mate!!}}$

$\large{(21m-15)}^3$

$\large{\blue{using\:(a-b)^3=a^3-b^3-3ab(a-b)}}$

$\large{(21m)^3-(15)^3-3(21m)(15)(21m-15}$

$\large{9261m^3-3375-945m(21m-15)}$

$\huge{9261m^3-3375-19845m^2+14175m}$