Question

A line passes through the points (-9,-13) and (2,20). Write its equation in a slope intercept form.

Answer 1

y = 3x + 14

Explanation:

the equation of a line in slope- intercept form is

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

calculate m using the slope formula

m =
`(y_(2)-y_(1) )/(x_(2)-x_(1) )`

let (x₁, y₁ ) = (- 9, - 13 ) and (x₂, y₂ ) = (2, 20 )

substitute these values into the formula for m

m =
`(20-(-13))/(2-(-9))` =
`(20+13)/(2+9)` =
`(33)/(11)` = 3 , then

y = 3x + c ← is the partial equation

to find c, substitute either of the 2 points into the partial equation

using (2, 20 )

20 = 3(2) + c = 6 + c ( subtract 6 from both sides )

14 = c

y = 3x + 14 ← equation of line