Question

How do you expand `(2x+2y)^4`?

Answer 1

`16x^4+64x^3y+96x^2y^2+64xy^3+16y^4`

Explanation:

Since `(a+b)^4=a^4+4a^3b+6a^2b^2+4ab^3+b^4`,

then `(2x+2y)^4=(2x)^4+4(2x)^3(2y)+6(2x)^2(2y)^2+4(2x)(2y)^3+(2y)^4`

that is

`16x^4+64x^3y+96x^2y^2+64xy^3+16y^4`