Find Equations for Straight Line Graphs

The gradient and intercept of any line can be stated by looking carefully at its equation.

For the line with equation y = mx + c, the gradient is m and the intercept on the y-axis is c.

m is the coefficient of x when in the form y = 

c is the number on its own

Example

Draw the line which is represented by y = 2x + 1

Answer

Comparing y = 2x + 1 to y = mx + c, we see that m = 2 and c = 1

Therefore, the gradient of the line (m) is 2 and the intercept (c) is 1.

This means that the line crosses the y-axis at (0, 1) 

The gradient of a line means the vertical ÷ horizontal. So, with a gradient of 2, we must have a line that goes 2 up and 1 to the right of the y intercept (0,1)

This gives us a point of (1,3). If we draw a straight line that passes through (0,1) and (1,3) we should have drawn the line for the equation y = 2x + 1

The line is shown below:

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