1. For the straight line y = -2x + 3, what are: 
a) the slope = -2

b) the y-intercept? =3 

2. The equation of the straight line shown in the diagram is  ( y = (½)x - 2 

First find the Slope or Gradient (these are two names for the same thing):

Slope = change in y / change in x = 2/4 = 1/2

So m = ½

Now find the y-intercept:

y-intercept = -2

So b = -2

The general equation of a straight line is y = mx + b

So the given line has equation y = (½)x - 2

3. What is the equation of the following line?

y = 0.75x + 2From the graph we can see m = rise/run = 3/4 = 0.75 and b is the y-intercept, so b = 2

Substitute into y = mx + b

Therefore y = 0.75x + 2 

4. The equation of the graph y= -4+2

From the graph we can see m = rise/run = -4/1 = -4 and b is the y-intercept, so b = 2

Substitute into y = mx + b

Therefore y = -4x + 2; 

5. For the straight line x = 2y - 3, what are: 

a) the slope

b) the y-intercept?

From the graph we can see m = rise/run = -4/1 = -4 and b is the y-intercept, so b = 2

Substitute into y = mx + b

Therefore y = -4x + 2

6. What is the equation of the straight line shown in the diagram is y  = -4/3x-4

First find the Slope (also called the Gradient):

Slope = (change in y) / (change in x) = -4/3

Now find the y-intercept:

y-intercept = -4

So b = -4

The general equation of a straight line is y = mx + b

So the given line has equation 

y = -4/3x - 4

7. What is the equation of the straight line shown in the diagram?

The straight line passes through ... (-5, 4), (-4, 4), (-3, 4), (-2, 4), (-1, 4), (0, 4), (1, 4), (2, 4), (3, 4), (4, 4), (5, 4) ...

Every point on the line has y coordinate equal to 4

Therefore the equation of the line is y = 4

8. What is the equation of the straight line shown in the diagram? x = -3 The straight line passes through ... (-3, 5), (-3, 4), (-3, 3), (-3, 2), (-3, 1), (-3, 0), (-3, -1), 
(-3, -2), (-3, -3), (-3, -4), (-3, -5) ...

Every point on the line has x coordinate equal to -3

So the equation of the line is x = -3

9. What is the equation shown in the diagram? of the straight line y = 3x - 5

First find the Slope (also called the Gradient):

Slope = (change in y) / (change in x) = 6/2 = 3

So m = 3

Now find the y-intercept:

y-intercept = -5

So b = -5

The general equation of a straight line is y = mx + b 
So the given line has equation y = 3x - 5

10.  What is the equation of the straight line shown in the diagram y = -0.6x + 2.5 

First find the Slope (also called the Gradient):

Slope = (change in y) / (change in x) = -3/5 = -0.6

So m = -0.6

Now find the y-intercept:

y-intercept = 2.5

So b = 2.5

The general equation of a straight line is y = mx + b

So the given line has equation y = -0.6x + 2.5