# How do you evaluate the expression 8+6r given r=7?

Jul 2, 2016

Substitute 7 for the $r$ and calculate the value of the expression to be 50.

#### Explanation:

The word evaluate means "find the value of".

In algebra, the variables represent numbers and when we know what that value is, we can replace the variable by a number and calculate a value for the expression.

$8 + 6 r$ means $8 + 6 \times r$

$= 8 + 6 \times \left(7\right)$

$= 8 + 42 = 50$