Slope is

Then you use the equation

Where b is the y-intercept. To find it, plug in x and y from one of the points. Say, point 1 (1,10):

You know m (from above) and now you can solve for b.
Rearrange terms:

And that will be the answer.
Make sense?
Answer:
That can be re-written:
x^2 + 5x -8 = 0
We use the Quadratic Formula
a=1
b = 5
c = -8
x = [-b +- sq root (b^2 - 4ac) ] / 2a
x = [-5 +- sq root (25 - - 32)] / 2
x1 = [-5 + sq root (57)] / 2
x1 = 1.27491722
x2 = [-5 - sq root (57)] / 2
x2 = -6.2749172176
Step-by-step explanation: