## College Algebra 7th Edition

$(5+3y)(25-15y+9y^2)$
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: $=(5+3y)[5^2-(5)(3y)+(3y)^2] \\=(5+3y)(25-15y+9y^2)$