Answer
$9x^{2}+6x+1$
Work Step by Step
$(3x+1)^{2}$
1. Square the first term. $(3x)^{2} = 9x^{2}$
2. Multiply the first term and second term inside the bracket together. Then multiply this answer by 2. So $(3x)(1)(2)=6x$
3. Square the last term inside the bracket. $(1)^{2} =1$
4. Add all your answers from steps 1-4 to get $9x^{2}+6x+1$.
