## Intermediate Algebra (6th Edition)

$36x^2+12x+1$
Using the square of a binomial, $(a+b)^2=a^2+2(a)(b)+b^2$, the given expression is equivalent to \begin{align*} & (6x+1)^2 \\\\&= (6x)^2+2(6x)(1)+1^2 \\\\&= 36x^2+12x+1 .\end{align*}