Question

Find the equation of the line that passes through the points (-1,8)

and (2, -1). Write your equation in slope-intercept form. Show all
work to support your answer.

Answer 1

y = -3 * x + 5

Step-by-step explanation:

We start with the equation for slope-intercept y = mx + b -

Y is any y point on the line. X is any x point on the line. M is the slope of the line. B is the y-intercept of the line.

We first find the slope by using this equation (y2 - y1) / (x2 - x1) -

(8 - (-1)) / ((-1) - 2)

9 / (-3)

Slope = -3

Now we insert the slope into the equation -

y = -3 * x + b

As said before, Y is any y point on the line and X is any x point on the line, so we can choose a random point and insert it in to find the y-intercept -

-1 = -3 * 2 + b

-1 = -6 + b

b = 5

The y-intercept of the line is (0, 5)

We insert the y-intercept in the equation -

y = -3 * x + 5

y = -3 * x + 5 is our answer to the problem.