Question

What is the slope of a line that is perpendicular to the line whose equation is 5y+2x=12?

A. 5/2
B. −2/5
C. −5/2
D. 2/5

Answer 1

A

Explanation:

The equation of a line in slope- intercept form is

y = mx + c ( m is the slope and c the y- intercept )

Rearrange 5y + 2x = 12 into this form

Subtract 2x from both sides

5y = - 2x + 12 ( divide all terms by 5 )

y = -
`(2)/(5)` +
`(12)/(5)` ← in slope- intercept form

with slope m = -
`(2)/(5)`

Given a line with slope m then the slope of a line perpendicular to it is

`m_(perpendicular)` = -
`(1)/(m)` = -
`(1)/(-(2)/(5) )` =
`(5)/(2)` → A