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: 1 y = x - 4 2 y = -x + 9 31 2 3 4 5 6 7 8 9 10 -9 -8 -7 -6 -5 -4 -3 -2 -1
-10 x y 1
y = x - 4 2
y = -x + 9 3
y = -2x + 4 4
y = -½x 5
y = ½x + 3 6
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. Find the gradients and intercepts of these equations:
Straight Lines
Find the gradients and intercepts of these equations:
y - x = 4
Gradient _____
y intercept _____
2. y + 2x = 3
y + 3x = - 8
4. y - 4x = -6
y - 4x = 8
x + 2y = 6 2 -2 3 -¾ -2 4 -6 1 3 2 3 1 2 3

6. Straight Lines Worksheet 1 Name the equation: 1 2 3 4 5 6 y x 1 2 3 41 2 3 4 5 6 7 8 9 10 -9 -8 -7 -6 -5 -4 -3 -2 -1
-10 x y 1 2 3 4 5 6

7. Straight Lines
Worksheet 2
Find the gradients and intercepts of these equations:
y - x = 4
Gradient _____
y intercept _____
2. y + 2x = 3
y + 3x = - 8
4. y - 4x = -6
y - 4x = 8
x + 2y = 6