Question

The points (–9,s) and (–6,–10) fall on a line with a slope of –4. What is the value of s?

Answer 1

Explanation:

We can set up an equation for this line using slope intercept form:

`y = mx + b`

Where
`m` is the slope of the line and
`b` is the y-intercept (where the line cross the Y-axis at
`x = 0`).

We know that the slope of the line is
`-4` so we can plug that in for
`m`, but we don't know
`b`, so we'll have to use the given point
`)(-6, -10)` to help solve for it:

`y = -4x + b`

`-10 = -4(-6) + b`

`-10 = 24 + b`

`b = -34`

This means the equation of the line is
`y = -4x - 34`. Now we can plug in the point
`(-9, s)` and solve for
`s`:

`y = -4x - 34`

`s = -4(-9) - 34`

`s = 36 - 34`

`s = 2`