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

9$s^{2}$+54s+81
Formula: $(a+b)^{2}$=$a^{2}$+2ab+$b^{2}$ We substitute the values in the formula and simplify: $(3s+9)^{2}$=$3s^{2}$+(2)(3s)(9)+$9^{2}$ =3$s^{2}$+54s+81