# What is the slope of a line that is perpendicular to the graph of : y= -1/2x + 4?

The slope is $2$

#### Explanation:

Lets say we have two lines

$y = {m}_{1} \cdot x + {b}_{1}$

$y = {m}_{2} \cdot x + {b}_{2}$

In order to be perpendicular we must have

${m}_{1} \cdot {m}_{2} = - 1$

Hence in the equation given we have ${m}_{1} = - \frac{1}{2}$ so we have

$\left(- \frac{1}{2}\right) \cdot {m}_{2} = - 1 \implies {m}_{2} = 2$