The y-intercept is simply the name of the point where the line passes through the y-axis. Since you already stated that that point comes at -1, we know the intercept is -1.
The answer would be $796 because your down payment is $100 plus the fact marge had to pay $58 for 12 months there for equaling $696 dollars for the 12 month then adding your down payment of $100 giving you your answer of $796!
