Expand and Simplify

a) (𝑎 + 2𝑏)^4
b) (3𝑥 + 𝑦)^3

review Pasal's Triangle. The row for 4th power is 1 4 6 4 1, so

(a+2b)^4 = a^4 + 4a^3(2b) + 6a^2(2b)^2 + 4a(2b)^3 + (2b)^4
= a^4 + 8a^3b + 24a^2b^2 + 32ab^3 + 16b^4

do others in like wise