Year 9 Interactive Maths - Second Edition

Equation of a Straight Line

The equation, y = mx + c, of a straight line is obtained by finding the gradient, m, and the y-intercept, c.

Example 11

Write the equation of the straight line that has gradient 2 and y-intercept 4.

Solution:

The general equation for a straight line is

y = mx + c

where m is the gradient and c is the y-intercept.

Putting m = 2 and c = 4, we get

y = 2x + 4

Example 12

Find the equation of the straight line given in the accompanying diagram.

Solution:

The general equation of a straight line is

Study Another Topic in Chapter 4: Linear Graphs

[ Linear Functions ] [ Gradient of a Straight Line ] [ Sketch Graphs ] [ Horizontal Lines ] [ Vertical Lines ] [ Equation of a Straight Line ] [ Half-Planes ] [ Problem Solving Unit ] [ Projects ] [ Symbols ] [ Index ]