Question

How do you graph `y - 7 = -3x` by plotting points?

Answer 1

Refer to the explanation below.

Explanation:

`y - 7= -3x`

First begin by rearranging the equation to form a linear function.

`y - 7= -3x`

`y = -3x + 7`

Now, looking at the equation you can see that:

• the gradient is negative due to the `-3`
• the graph has been shifted up by `7`

Now, find the point of intersection of the graph along the `y`-axis by making `x = 0`.

`y = -3x + 7`

`y = -3(0) + 7`

`y = 0 + 7`

`y = 7`

Therefore, `(0,7)` is your point of intersection of the graph with the `y`-axis.

Now, find the point of intersection of the graph along the `x`-axis by making `y = 0`.

`y = -3x + 7`

`0 = -3x + 7`

`0 - 7 = -3x`

`(-7) / -3 = (-3x)/-3`

`x = 2.33333`

Now sketch the complete graph.

graph{y - 7= -3x [-4.98, 15.01, -1.88, 8.12]}