**Equations of lines**

Starter

3x + 2y = 12

Activity

Gradient and intercept

3x + 2y = 12

**L.O. - Use equations of lines in unfamiliar formats and find gradient and intercept.**

How do we know that this is a straight line?

Work out y when x = 0

Work out y when x = 1

Starter

3x + 2y = 12

How do we know that this is a straight line?

No powers involved with x or y.

Work out y when x = 0.

2y = 12 y = 6.

Work out y when x = 1

2y = 9 y = 4.5

What is the gradient of the line?

What is the y-intercept of the line?

Gradient and intercept

3x + 2y = 12

What is the gradient of the line?

What is the y-intercept of the line?

x = 0

y = 6

x = 1

y = 4

6 - 4 = -1

-1

1

2

6

Gradient and intercept

5y - 4x = 20

What is the gradient of the line?

What is the y-intercept of the line?

Gradient and intercept

5y - 4x = 20

What is the gradient of the line?

What is the y-intercept of the line?

4

5

4

5

4

Evaluate these equations at x = 0 and x = 1 and hence find the gradient and y intercept of the line.

a) 2x - y = 6 f) 4x + 2y = 9

b) 3x - y = 4 g) 3x + 2y = 8

c) 4x - 2y = 10 h) 7x - 3y = 9

d) 6x - 2y = 2 i) 3x - 5y = 7

e) 5x - 2y = 6 h) 4x + 7y = 9

1

2

1

2

1

2

x = 0

y = 4

x = 1

y = 3

4 - 3 =

1

5

1

5

Activity

Evaluate these equations at x = 0 and x = 1 and hence find the gradient and y intercept of the line.

a) 2x - y = 6 f) 4x + 2y = 9

b) 3x - y = 4 g) 3x + 2y = 8

c) 4x - 2y = 10 h) 7x - 3y = 9

d) 6x - 2y = 2 i) 3x - 5y = 7

e) 5x - 2y = 6 h) 4x + 7y = 9

gradient

y-intercept

gradient

y-intercept

2

-6

3

-4

2

-5

3

-1

2

-3

1

2

-2

4

-1

4

2

-3

-1

-1

1

2

2

3

3

5

4

7

1

2

2

5

2

7

**Activities**

**Activity**

Answers

Answers

**Key**

Examples

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**Worked**

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