Question

What is the equation of the line with slope `m= -2` that passes through `(5,-8)`?

Answer 1

I assume you are using slope-intercept form.

Explanation:

Slope-Intercept form looks like this: y=mx+b, and since we already know the slope and m is the slope's value, we plug in the slope for m. Our equation now looks like:
y=-2x+b.
All we have to do now is find the value of b (the y-intercept.) In the final equation y will be left as y and x as x.
To find b we plug in the coordinate. -8 for y and 5 for x.
So,
-8=-2(5)+b
-8=-10+b
2=b

Now that we have the b value we are almost done. All we need to do is write out our final equation. Plug in 2 for b and -2 for m and you should get:

y=-2x+2

Hope this helps!