Algebra 1 · Grades 8 to 9
Linear functions and slope
Find slope and write the equation of a line.
The idea
A linear function makes a straight line. Its slope measures how steep the line is: the change in y divided by the change in x.
The form y = mx + b gives the slope m and the y-intercept b. Two points are enough to find the slope and write the equation.
Worked examples
- How to Find the Slope from Two Points Find the slope of the line through (1, 2) and (4, 11). Four steps with the slope formula, the reasons, and the order mistakes to avoid.
- How to Write the Equation of a Line Write the equation of the line with slope 2 through (3, 7). Four steps with point-slope form, the reasons, and the sign mistakes to avoid.
- How to Find the Intercepts of a Line Find the x- and y-intercepts of 2x + 3y = 12 in four steps. Set each variable to zero, and see the intercept mistakes students make.
Practice this topic
3 problems with answers.