Question

http://prntscr.com/3hy79c

Answer 1

hmm so we start with $685 and we deposit and withdraw from times to times.
deposit means we put more money in balance (adding) and withdraw means we took money out of balance (subtract)

Answer 2

so first we deposit $175 into balance, so that mean we add $175 to $685.
for second, we withdraw $240 from balance, so that means balance - 240

Answer 3

makes sense?