The equation for the total is T = 4250 *1.07^7
She starts off with 4250(100%). After 1 year she would have 107%. After 2 years, it’s that 107% times another 107% or 1.06^2 and so on.
A) $6824.57
“x amount of money she starts with times 7% interest over 7 years, minus the amount of money she started with equals 3500 in interest”
(x * 1.07^7) - x = 3500
x * 1.60578147648 - x = 3500
1.60578147648x - x = 3500
0.60578147648x = 3500
x = 5777.66098154
B) $5777.66