Question

Write an equation of a line in slope intercept form (y = mx + b) going through the points

(-2, 0) and (4, -3). Show your work for full credit.

Answer 1

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

Explanation:

The equation of a line in slope- intercept form is

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

Calculate m using the slope formula

m = (y₂ - y₁ ) / (x₂ - x₁ )

with (x₁, y₁ ) = (- 2, 0) and (x₂, y₂ ) = (4, - 3)

m =
`(-3-0)/(4+2)` =
`(-3)/(6)` = -
`(1)/(2)`, thus

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

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

Using (- 2, 0 ), then

0 = 1 + b ⇒ b = 0 - 1 = - 1

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