Question

write in slope intercept form the equasion of the line that is perpendicular to the line y=-1/2x+1 and passes through the point (8,5)

Answer 1

y = 2x - 11

Explanation:

The equation of a line in slope- intercept form is

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

y = -
`(1)/(2)` x + 1 ← is in slope- intercept form

with slope m = -
`(1)/(2)`

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

`m_(perpendicular)` = -
`(1)/(m)` = -
`(1)/(-(1)/(2) )` = 2 , then

y = 2x + c ← is the partial equation

To find c substitute (8, 5) into the partial equation

5 = 16 + c ⇒ c = 5 - 16 = - 11

y = 2x - 11 ← equation of perpendicular line