Question

a line intercects the points (-22,-14) and (-18,-12). what is the slope intercept equation for this line?

Answer 1

y =
`(1)/(2)` x - 3

Explanation:

The equation of a line in slope- intercept form is

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

To calculate m use the slope formula

m = ( y₂ - y₁ ) / ( x₂ - x₁ )

with (x₁, y₁ ) = (- 22, - 14) and (x₂, y₂ ) = (- 18, - 12)

m =
`(-12+14)/(-18+22)` =
`(2)/(4)` =
`(1)/(2)`

y =
`(1)/(2)` x + c ← is the partial equation

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

using (- 22, - 14), then

- 14 = - 11 + c ⇒ c = - 14 + 11 = - 3

y =
`(1)/(2)` x - 3 ← in slope- intercept form