# How do you write (6x^3 − 8x − 5) + (3x^3 + 6x + 2) in standard form?

Jul 2, 2018

$9 {x}^{3} - 2 x - 3$

#### Explanation:

Don't forget to get the signs right.
If the sign before the second bracket was a minus then you would have to multiply through by -1.
( i.e. everything in the second brackets would change sign when the brackets are removed)
(+- makes -, -+ makes -, ++ makes +, -- makes +)

Group all terms of the same type together
(${x}^{3}$ can only be added to ${x}^{3}$ etc.)
Note: this is not the same if multipying (e.g.$6 {x}^{3} \cdot 3 {x}^{2} = 18 {x}^{5}$)

$6 {x}^{3} + 3 {x}^{3} - 8 x + 6 x - 5 + 2$
$9 {x}^{3} - 2 x - 3$