## Calculus with Applications (10th Edition)

$(a-6)(a^2+6a+36)$
RECALL: $a^3-b^3 = (a-b)(a^2+ab+b^2)$ Write 216 as a cube to have: $=a^3-6^3$ Factor the difference of two cubes using the formula above with $a=a$ and $b=6$ to have: $=(a-6)(a^2+a(6) + 6^2) \\=(a-6)(a^2+6a+36)$