Question

Evaluate . With steps fast
$64 {x}^{3} + \sqrt{125} {y }^{3}$

Answer 1

64x^3 +√125y^3

= ( 4x )^3 + (5√5y)^3

now use identity:-

a^3 + b^3 =( a + b ) ( a ^2 - ab + b^2 )

here, a = 4x , b = 5√5y

=( 4x + 5√ 5y ) { 16x^2 - 20 √5 x y + 125 y^2}

◆hope it helps◆