consider the following transaction in detail:
Deposited amount by paycheck - $489.50
Deposited amount by stock dividend check - $x
Deposited amount by dollar rebate check - $y
Deposited amount in his checking account - $85
And original amount before deposits - $w
To get total amount in his account, we have to add all of the above transactions.
That is balance in his account after deposits = 489.5+x+y+85+w
= 574.5+x+y+w $