# How do you find the slope that is perpendicular to the line y = (-4/5)x + 1?

Aug 2, 2016

The slope of the perpendicular line is $\frac{5}{4}$

#### Explanation:

Here the slope of the line is ${m}_{1} = - \frac{4}{5}$. Let the slope of the perpendicular line be ${m}_{2}$. We know condition of perpendicularity of two lines is ${m}_{1} \cdot {m}_{2} = - 1 \mathmr{and} {m}_{2} = - \frac{1}{m} _ 1 = - \frac{1}{- \frac{4}{5}} = \frac{5}{4}$[Ans]

Aug 2, 2016

$+ \frac{5}{4}$

#### Explanation:

Consider the standard form equation of: $\text{ } y = m x + c$
where $m$ is the gradient (slope).

A line perpendicular to this has the gradient $\text{ } \left(- 1\right) \times \frac{1}{m} = - \frac{1}{m}$

In your equation $m = - \frac{4}{5}$

So $- \frac{1}{m} = + \frac{5}{4}$