Question

A line passes through the points (2, -2) and (8, 1).

Click “show your work” and provide work for calculating the slope and y-intercept. Then, write the equation for the line in slope-intercept form. Please write your answers on the lines provided on the whiteboard.

Answer 1

• Slope: 1/2
• Y-intercept: -3
• Equation: y = 1/2x -3

Explanation:

You want the slope, y-intercept, and equation for a line that passes through the points (2, -2) and (8, 1).

Slope

The slope formula is used to find the slope:

m = (y2 -y1)/(x2 -x1)

m = (1 -(-2))/(8 -2) = 3/6 = 1/2

Y-intercept

The slope-intercept equation can be rearranged to give the y-intercept:

b = y - mx

b = 1 -(1/2)(8) = 1 -4 = -3 . . . . . . using (x, y) = (8, 1)

Slope-Intercept Form

The slope-intercept form equation is ...

y = mx +b . . . . . . where m is the slope, and b is the y-intercept

Using the found values, the equation is ...

y = 1/2x -3

Summary

• Slope: 1/2
• Y-intercept: -3
• Equation: y = 1/2x -3