# How do you factor the expression 125x^3 + 343y^3?

Dec 10, 2015

Factor: $125 {x}^{3} + 343 {y}^{3}$
Ans: $\left(5 x + 7 y\right) \left(25 {x}^{2} - 35 x + 49 {y}^{2}\right)$
Use the algebraic identity: ${a}^{3} + {b}^{3} = \left(a + b\right) \left({a}^{2} - a b + {b}^{2}\right)$
$125 {x}^{3} + 343 {y}^{3} = \left(5 x + 7 y\right) \left(25 {x}^{2} - 35 x y + 49 {y}^{2}\right)$