# How do you write (x^2 + 4x – 3)(2x^2 + x + 6) in standard form?

Dec 12, 2017

$2 {x}^{4} + 9 {x}^{3} + 4 {x}^{2} + 21 x - 18$

#### Explanation:

This is a long one, but it's not difficult, as long as we watch our signs

$\left({x}^{2} + 4 x - 3\right) \left(2 {x}^{2} + x + 6\right)$

$2 {x}^{4} + {x}^{3} + 6 {x}^{2} + 8 {x}^{3} + 4 {x}^{2} + 24 x - 6 {x}^{2} - 3 x - 18$

combine like terms:

$2 {x}^{4} + \left(1 {x}^{3} + 8 {x}^{3}\right) + \left(6 {x}^{2} + 4 {x}^{2} - 6 {x}^{2}\right) + \left(24 x - 3 x\right) - 18$

$2 {x}^{4} + 9 {x}^{3} + 4 {x}^{2} + 21 x - 18$