Unit 3 - Slope-intercept form given two points

Unit 3 - Slope-intercept form given two points

Write the equation of a line in slope-intercept form that passes through the point (2,5) and has a slope of 4.

• y = mx + b

• y = 4x + b

• 5 = 4(2) + b

• 5 = 8 + b, subtract 8 from both sides...b = -3

• y = 4x - 3

Fill in the Blanks

Determine the slope of the line given the following points: (2,5) and (4, 13).

• Rise over Run translates to change in y over change in x.

• (y2 - y1) / (x2 - x1)

• x1 = 2, y1 = 5, x2 = 4, y2 = 13

• y2 - y1, 13 - 5 = 8

• x2 - x1, 4 - 2 = 2

• 8/2 = 4/1 or 4

• slope or m = 4

Slope-Intercept Form

Example of a linear equation in slope-intercept form.

Determining slope of a linear function.

Write the equation of the line through the points (2, 5) and (4,13).

Take one of the two ordered pairs and use the x and y values to substitute into the equation. Solve for b (y-intercept).

Substitute the one of the two ordered pairs back into the equation for x and y and evaluate both sides. Check graphically as well.

Check Algebraically.

Check Graphically using desmos.

• https://www.desmos.com/calculator