How do you combine $12 - (y^3 + 4)$ ?

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Answer 1 · 2015-04-29T16:26:39

$12 - (y^3 + 4)$

$= 12 - y^3 - 4$

$= -y^3 + 8$

$= -(y^3 - 8)$

$= -(y^3 - 2^3)$

We know that $color(blue)(a^3 - b^3 = (a-b)(a^2+ab+b^2)$

$= (y-2)(y^2+2y +2^2)$

$=color(green)( (y-2)(y^2+2y +4)$

How do you combine 12 - (y^3 + 4)12 - (y^3 + 4)?