Question

(4 x + 2 y) cube minus (4 x minus 2 y) cube

Answer 1

Answer:

The answer is $19x^2y+16y^3$

Step-by-step explanation:

Using $a^3-b^3=(a-b)(a^2+b^2+ab)$

We have,

$(4x+2y)^3-(4x-2y)^3\\=[(4x+2y)-(4x-2y)][(4x+2y)^2+(4x-2y)^2+(4x+2y)(4x-2y)]\\=(4x+2y-4x+2y)(16x^2+4y^2+16xy+16x^2+4y^2-16xy+16x^2-4y^2)\\=(4y)(48x^2+4y^2)=19x^2y+16y^3$