Answer:
(7x +6y)(49x^2 -42xy +36y^2)
Step-by-step explanation:
The factoring of the sum of cubes is a special form:
a³ +b³ = (a +b)(a² -ab +b²)
We recognize the given expression as a sum of cubes, so we can use this pattern to factor it.
From our memory of the cubes of small numbers (or from the cube root function of our calculator), we can identify the terms as ...
343x³ +216y³ = (7x)³ +(6y)³
Our factoring pattern above can be used with ...
Substituting these values, we have ...
343x³ +216y³ = (7x)³ +(6y)³ = (7x +6y)((7x)² -(7x)(6y) +(6y)²)
343x³ +216y³ = (7x +6y)(49x² -42xy +36y²)