Question

What is the slope intercept form for a line that passes through (-1,1) and (2,-11)

Answer 1

y = - 4x - 3

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, 1) and (x₂, y₂ ) = (2, - 11)

m =
`(-11-1)/(2+1)` =
`(-12)/(3)` = - 4 , then

y = - 4x + c ← is the partial equation

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

Using (- 1, 1 ), then

1 = 4 + c ⇒ c = 1 - 4 = - 3

y = - 4x - 3 ← equation of line

Answer 2

Answer: y = −4 x − 3

Explanation:

First change it into point slope form which is y − 1 = − 4 ⋅ (x + 1 )

The change it from point slope form to slope intercept which is y = −4 x − 3