# What is the standard form of  y= (x-3)(4x+8)-(x-4)(x+2)?

Feb 17, 2016

Multiply long hand simplify to get:
$3 {x}^{2} - 2 x - 16$

Feb 17, 2016

$3 {x}^{2} - 2 x - 16$

#### Explanation:

distribute the 1st 'pair' of brackets using FOIL (or any method you use).

(x-3)(4x+8) = $4 {x}^{2} + 8 x - 12 x - 24 = 4 {x}^{2} - 4 x - 24$

Similarly for the 2nd 'pair' of brackets.

$\left(x - 4\right) \left(x + 2\right) = {x}^{2} + 2 x - 4 x - 8 = {x}^{2} - 2 x - 8$

now have : $4 {x}^{2} - 4 x - 24 - \left({x}^{2} - 2 x - 8\right)$

$= 4 {x}^{2} - 4 x - 24 - {x}^{2} + 2 x + 8 = 3 {x}^{2} - 2 x - 16$