# How do you evaluate the expression 2x^2+3x+9 if x=-3?

Dec 6, 2016

#### Answer:

$18$

#### Explanation:

You substitute $- 3$ for every occurrence of $x$ in the expression and then calculate the result. Be sure to handle the signs of numbers correctly:

$2 \left(- {3}^{2}\right) + 3 \left(- 3\right) + 9 \to$

$\left(2 \cdot 9\right) - 9 + 9 \to$

$18 - 0 \to$

$18$