Question

You deposited $45.25 in your checking account, but instead of adding $45.25 to your balance, the bank accidentally subtracted $45.25. How much money should the bank add to your account to correct the mistake?

Answer 1

The bank must add `$90.50` to correct the mistake.

Explanation:

If we consider the original amount in the checking account as `x`, then the amount after you deposited `$45.25` would have been:

`(x+45.25)`

Since the bank accidentally subtracted the amount, the actual amount now is:

`(x-45.25)`

To rectify this, the bank has to first restore the `45.25` that it subtracted and then add the `45.25` which you deposited. In short, the bank will have to add:

`45.25+45.25=90.50`

Answer 2

`$90.50`

Explanation:

The target value in the account is `+$45.25`

The error results in it being `-$45.25`

So we have to change `-$45.25" into "+$45.25`

So we have:

`color(green)("correction "-$45.25=+$45.25)`

To find the value of "correction" add `color(red)($45.25)` to both sides

`color(green)("correction "color(red)(+$45.25)-$45.25" "=" "+$45.25color(red)(+$45.25))`

`color(green)("correction "+0" "=" "+$45.25color(red)(+$45.25))`

`color(green)("correction "=" "$90.50)`