(4a+2k) squared

Question

It is so hard and tricky. I tried to solve it.

Answer 1

(4a+2k)^2 =

16a^2 + 16ak + 4k^2

square the 1st term: (4a)^2 = 16a^2

square the last term: (2k)^2 = 4k^2

multiply the two terms together and double it: 2(4a)(2k) = 16ak

add them all together: 16a^2 + 16ak + 4k^2