Question

A line with a slope of -7 passes through the points (u,0) and (8,-7) what is the value of u?

Answer 1

u = 7

Explanation:

Using the slope intercept formula:

`(y2 - y1)/(x2 - x1)  = slope`

Substitute our values from the points and the known slope:

`(-7 - 0)/(8 - u) = -7`

Now we multiply both sides by (8 - u) to isolate the x:

(8-u) x
`(-7)/(8 - u)` = -7 (8 - u)

Next we add 56 to both sides:

-7 = -56 + 7u

Finish off by dividing both sides by 7:

7u = 49

u = 7