Question

Write a linear equation in point slope form the line that goes through (-1,1) and (1,-5).

Answer 1

D.

`y - 1 = - 3(x + 1)`

EXPLANATION

The point-slope form equation is calculated using the formula:

`y-y_1=m(x-x_1)`

Where m is the slope, which is calculated using the formula:

`m = (y_2-y_1)/(x_2-x_1)`

Let

`(x_1,y_1)=(-1,1)`

and

`(x_2,y_2)=(1, - 5)`

We substitute the points to obtain;

`m = ( - 5 - 1)/(1 - - 1)`

`m = ( - 6)/(2) = - 3`

We also substitute the point and slope to obtain;

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

Simplify the expression in the parenthesis to get;

`y - 1 = - 3(x + 1)`

The correct choice is D.

Answer 2

Answer: Option D.

Explanation:

The equation of the line in point-slope form is:

`y-y_1=m(x-x_1)`

Where m is the slope of the line and (
`x_1,y_1`) is a point of the line.

Given the points (-1,1) and (1,-5), you can find the slope with the formula
`m=(y_2-y_1)/(x_2-x_1)`. Then:

`m=(-5-1)/(1-(-1))=(-6)/(2)=-3`

Substitute the slope and the point (-1,1) into
`y-y_1=m(x-x_1)`:

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

`y-1=-3(x-+1)`