Straight Lines

1
Straight Lines
Objectives C Grade Find the gradients and
y-intercepts of equations in the form 4y 3x
8 by rearranging the equation
Prior knowledge Recognise the equations of
straight line graphs and find the
gradients of straight line graphs
Rearrange equations to make a variable the subject
2
Straight Lines
Name the equation
y x - 4
y -x 9
y -2x 4
y -½x
y ½x 3
y 2x - 3
3
Straight Lines
Example 1
Rearrange this equation into the form y mx c
y x 8
Use the inverse function to move x to the other
side of the equation
Example 2
-x
y 8 - x
Rearrange this equation into the form y mx c
2y 4x 8
Use the inverse function to move x to the other
side of the equation
-4x
2y 8 - 4x
Use the inverse function to get y
2
y 8 - 4x 2
Simplifies to y 4 2x
4
Straight Lines
Find the gradient of this straight line and where
it crosses the y-axis
y 3x 6
Rearrange this equation into the form y mx c
y -3x 6
-3
6
The gradient is
The y intercept is
5
Straight Lines
2
½
3
-2
-2
-¾
4
-6
3
6
Straight Lines
Worksheet 1
Name the equation
7
Straight Lines
Worksheet 2