## Algebra 1: Common Core (15th Edition)

$9x^{2}-24x+16$.
The area of a square with side a: $A=a^{2}$ ...substitute $(3x-4)$ for $a$. $A=(3x-4^{2})$ ...square the binomial. $A=(3x^{2})-2(3x)(4)+4^{2}$ ...simplify. $A=9x^{2}-24x+16$ The area of the base is $9x^{2}-24x+16$.