Answer
$(5+3y)(25-15y+9y^2)$
Work Step by Step
RECALL:
A sum of two cubes can be factored using the formula
$A^3+B^3=(A+B)(A^2-AB+B^2)$
The given binomial can be written as:
$=5^3+(3y)^3$
The binomial is a sum of two cubes.
Factor using the formula above with $A=5$ and $B=3y$ to obtain:
$=(5+3y)[5^2-(5)(3y)+(3y)^2]
\\=(5+3y)(25-15y+9y^2)$
