Probably going to be asking a few different questions as theyarrive, I have a lot of work to make-up for class.

1st one is-

What would be my variables in this story problem.

Reliable Rentals rents cars for $12.95 per day plus $0.15 per miles. Luis Romero works for a company that limits expenses for car rentals to $90 per day. What is the maximum number of miles that Mr. Romero can drive each day?

One would be miles

The other would be days? I'm not sure.

Number of miles is the only variable. Let's call it N

Total amount that you can spend per day is $90
Base charge for the rental is $12.95
Cost per mile is $0.15

$90 = $12.95 + $0.15 * N

Oh wow I derped, thanks.

Next, what's an easy method to find a point on a line with not so nice x and y intercepts?

Example - y=2/3x-5/3

Set x equal to 0, then calculate what the resulting y value would be, and now you have a point on that line: {0,result of calculation using x=0}

or in your specific example:
(I'm assuming that dash in front of the y is not a negative sign.... )
y = (2/3)*0 - (5/3)
y = -5/3
{0,-5/3}

This post was edited by Azrad on Oct 8 2013 05:23am