First the cost. We know that tuition per credit hour is 113.67 and there is a flat fee of 660. This can be represented by 113.67h + 660, where h is equal to the number of credit hours.
Next, the amount paid. There are two constants of 350 and 400 already there. We can represent the remaining amount that needs to be paid by another variable, x.
Now, the cost needs to be equal to the amount you pay. We can replace h with 15 for 15 hours and solve for x.
Usually, quadratic equations equal 0, and to find the solution you need to make x equal the value that, when added or subtracted to the rest of its bracket, makes 0. This means that your answer is (x + 5)(x - 2) = 0, because 5 - 5 = 0 and 2 - 2 = 0. I hope this helps! Let me know if you would like me to explain further :)
