Solving
S = 3F - 24
for F gives
S + 24 = 3F
(S + 24)/3 = F
The best choice is the last one:
F = (S + 24)/3
The common difference is 4. U know that the formula is the first term + d(n -1). N-1 is 14 so u know that 14 times a number needs to equal 56 because the first term is -3 and 56-3 is 53. 14 * 4 is 56. So the common difference is 4
It will take him 28 weeks. If he already has $60 of $200 saved, you would do 200 - 60. That would give you 140. To find out how long it would take him to make $140, you would have to do 140 divided by 5 to get the number of weeks.
