ANSWER
Find out the total deposit.
To proof
Let us assume that the total deposit be x.
As given
Nabora Nagamatus deposited a check for $ 299.45 and a check for 229.52.
He recieved $42 in cash.
than the equation is become in the form
x = 299.45 + 229.52 - 42
x = $486.97
therefore the total deposit be $486.97 .
Hence proved