(a+2b)^6 = a^6 + 6a^5(2b) + 15a^4(2b)^2 + 20a^3(2b)^3 + 15a^2(2b)^4 + 6a(2b)^5 + (2b)^6

(a+2b)^6 = a^6 + 12a^5b + 48a^4b^2 + 96a^3b^3 + 96a^2b^4 + 48ab^5 + 64b^6