Linear functions · Grades 9–10
Find a line from two points
Free worked example · No account needed
Example question
Find the line through (1, 3) and (5, 11).
Work through it
- 1
m = (11 - 3) / (5 - 1) = 2
Slope is change in y divided by change in x between the points.
- 2
y = 2x + b
Use slope-intercept form, where m is 2 and b is the y-intercept.
- 3
3 = 2(1) + b, so b = 1
Substitute the point (1, 3) into the line and solve for b.
Final answer
y = 2x + 1