If the scholarship pays 75% of her classes cost, that means that she has to pay the 25% remaining of the classes cost so if we calculate it as follow:
0.25 * $14,000 = $3,500
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Another method to understand:
if the scolarship pays 75% of her classes that will be
0.75* $14,000 = $10,500
now she has to pay the remaining of the total cost and that will be
$14,000 - $10,500 = $3,500.
4a + 3b - a - 5b
First, gather the like terms.
Second, subtract 4a - a to get 3a.
Third, subtract 3b - 5b to get 2b.

Answer:
3a - 2b
The bottoms are all multiples of seven