### Home > AC > Chapter 2 > Lesson 2.1.1 > Problem2-10

2-10.

One meaning of the word evaluate is to find the value of an expression. To evaluate, replace a variable with a number and calculate the result. For example, when you are asked to evaluate the expression $4x−2$ when $x=−7$, you would put $−7$ in place of the variable and calculate: $4(−7)−2=−30$
Evaluate the expressions below for the given values of $x$ and $y$.

Rewrite the expression with the number in place of the variable and simplify if possible.

1. $\frac{6}{x}+9$ if $x=3$

$\frac{ 6 }{(3) } + 9 =$

$\text{Remember }\frac{6}{3} \text{ is the same as }6 \text{ divided by }3.$

$11$

1. $8x−3+y$ if $x=2$ and $y=1$

$8(2)−3+(1)$

Try evaluating this one on your own. Think of the rules for multiplying positive and negative integers.

1. $2xy$ if $x=5$ and $y=−3$

$2(5)(−3)=10(−3)$

$−30$

1. $2x^2−y$ if $x=3$ and $y=8$

$2(3)^2−(8)$