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

1 Answer
Aug 30, 2016

16x^4+64x^3y+96x^2y^2+64xy^3+16y^416x4+64x3y+96x2y2+64xy3+16y4

Explanation:

Since (a+b)^4=a^4+4a^3b+6a^2b^2+4ab^3+b^4(a+b)4=a4+4a3b+6a2b2+4ab3+b4,

then (2x+2y)^4=(2x)^4+4(2x)^3(2y)+6(2x)^2(2y)^2+4(2x)(2y)^3+(2y)^4(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^416x4+64x3y+96x2y2+64xy3+16y4