To find the interest you multiply the amount of $ he loan times the interest
$14,000 X 0.8 or $14,000 x %8 either way you enter it in the calculator you get the same answer $11,200 that would be the amount he paid for the first year so since you want to find how much he paid for 7yrs you multiply the
$11,200 X 7= $78,400 that's the answer for the first question
the answer to the second to question b:
multiply the amount he paid the first year times 5
$11,200 x 5= $56,000
the amount of money he saved would be the difference between the first answer and the second answer
76,400-56,000=22,400
Hope it helps