# How do you evaluate 7b - 9 for b=9?

May 8, 2016

$= 54$

#### Explanation:

$7 b - 9$

The value of the variable is :
color(blue)(b = 9

Substituting the same in the expression.
$7 b - 9 = 7 \cdot \textcolor{b l u e}{9} - 9$

$= 63 - 9$

$= 54$