Question

How can I make this equation into an ordered pair

Answer 1

I'd suggest re-wording your question:
"How do I find the ordered pair (x,y) that solves this system of linear equations?"

One way of doing that would be to substitute y=5x+7 into the other equation:

-3x - 2(5x+7) = -12.  Solve this for x.  Once you have a value for x, subst. that value into y=5x+7 to find the corresponding y value.

Then write the ordered pair (x,y).  That's it.