Given:
Amount in the bank account = $1850
Monthly payment of can loan = $400.73
To find:
When would automatic payments make the value of the account zero?
Solution:
Craig stops making deposits to that account. So, amount $1850 in the bank account is used to make monthly payment of can loan.
On dividing the amount by monthly payment, we get

It means, the amount is sufficient for 4 payment but for the 5th payment the amount is not sufficient.
Therefore, the 5th automatic payments make the value of the account zero.
A) The result of adding the two equations is
.. (2.5y +3x) +(5x -2.5y) = (27) +(5)
.. 8x = 32 . . . . . . . . . . . . . . . . . . . . . . . your 2nd selection
b) The solution to the system is (4, 6), your 4th selection.
.. This is the only choice with x=4, the solution to part (a).
58% is about equal to 60%, 10% of 121 is 12.1.
12.1 * 6 = 72.6
To take this further, 58% is 2% less than 60%, or 2 times 1%. 1% of 121 is 1.21.
72.6 - (1.21 * 2) = 72.6 - 2.42 = 70.18