# How do you combine like terms in -3+ 7x + 4+ ( - 9x ) ?

May 14, 2017

Answer: $1 - 2 x$

#### Explanation:

We can only combine (add/subtract) terms with the same variable of the same degree. Here, $- 3$ and $4$ are both constants (no variable) and $7 x$ and $- 9 x$ have the same variable ($x$) to the first degree.

Therefore,
$- 3 + 7 x + 4 - 9 x$
By rearranging:
$= - 3 + 4 + 7 x - 9 x$
$= 1 - 2 x$