Question

The equation of the line that passes through the points (-1. 8) and (3,0) can be written in the form y = mx + c. Find the value of m and the value of c.

Answer 1

m = - 2 , c = 6

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) )`

with (x₁, y₁ ) = (- 1, 8 ) and (x₂, y₂ ) = (3, 0 )

m =
`(0-8)/(3-(-1))` =
`(-8)/(3+1)` =
`(-8)/(4)` = - 2 , then

y = - 2x + c ← is the partial equation

To find c substitute either of the 2 points into the partial equation

using (3, 0 )

0 = - 6 + c ⇒ c = 0 + 6 = 6