How do I find the equation of a straight line from a graph?

Let's use a general equation for straight lines, y= mx +c. Here, the m and c represent numbers (or constants), which will differ for each specific line. The number in the place of the m is the gradient of the line, or the slope. This is calculated by dividing the change in height along the y axis by the change in width along the x axis (sometimes called rise over run). The number in the place of the c is where the straight line crosses the y axis. If I draw an example, such as this graph, we can see that for each x coordinate that increases we go up 2 y coordinates, so our slope is 2/1=2 which we substitute for our letter m. We can also see that the line crosses the y axis at the number 1, so that is what we plug into our letter c, giving us the equation. y=2x+1

KM
Answered by Katherine M. Maths tutor

3363 Views

See similar Maths GCSE tutors

Related Maths GCSE answers

All answers ▸

How can I tell if two lines are perpendicular from the equations?


Jason and Mary leave their houses at the same time. They travel towards each other, Mary at 20km/h and Jason at 15km/h. They pass each other after an hour and a half. What was the original distance between them when they started?


What is mathematics and why should I study it?


How do I solve the inequality 7x+2 > 2x-3?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning