Question

flynn opens a saving account. In one 3 month period, he makes deposit of $75.50 and $55.25. He makes withdrawal of $25.15 and $18.65. His balance at the end of the 3 month period is $210.85. Explain how you can find his initial deposit amount?

Answer 1

x=initial deposit amount.
we have to add to the initial deposit amount the incomes and subtract the withdrawal
x+($75.5+$55.25)-($25.15+$18.65)=$210.85
Now we solve this equation.
x+$130.75-$43.8=$210.85
x+$86.95=$210.85
x=$210.85-$86.95
x=$123.9

Answer: his initial deposit amount is $123.9

Answer 2

By adding all of the amounts up: 75.00+55.25= 130.25, afterwords you need to add up the amount that Flynn spent, which is 25.15+18.65= 43.80, Once you have these two numbers. You need to subtract them from each other which looks like this: 130.25-43.80=86.45, then by subtracting that number from the last amount: 210.85-86.45=124.4. 
The initial deposit is: 124.4
And to check your answer, you have to add 130.25+124.4=254.65, and then: 254.65-43.80= 210.85.