Question

What can I do with a coordinations and the slope

Answer 1

You can plot a linear equation, if you are given the coordinates and the slope for THE SAME line.

Assuming you have those, the first step is to find the y-intercept.

That is done by replacing $x$ and $y$ in the general formula by their coordinated counterparts, and replacing $m$ by the slope that is given to you.

Let's assume the coordinates you are given are $(5,10)$, and the slope you are given is 1.

By substituting into the general formula...

$y=mx+c\\(10)=(1)(5)+c\\10=5+c\\10-5=c\\c=5$

...we can see that it is possible to find the y-intercept ($c$).

Knowing the y-intercept, it is possible to plot the line and solve any question.

I'll leave a picture of the example used above when graphed.