I believe the answer is -8
This is a ratio problem:
26/18 = 39/x
to solve for x cross multiply: 18 * 39 = 702 and then divide by 26
702 / 26 = 27
x = 27
Answer:
$487.20
The answer is $487.20 if he expects to deposits $830.
Answer: D
Over the interval [4,7], the local minimum is -7