Question

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

Answer 1

ANSWER

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:

$m = \frac{y_2-y_1}{x_2-x_1}$

Let

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

and

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

We substitute the points to obtain;

$m = \frac{ - 5 - 1}{1 - - 1}$

$m = \frac{ - 6}{2} = - 3$

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.

Step-by-step 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 $m=\frac{y_2-y_1}{x_2-x_1}$. Then:

$m=\frac{-5-1}{1-(-1)}=\frac{-6}{2}=-3$

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

 $y-1=-3(x-(-1))$

 $y-1=-3(x-+1)$