Fisrt Way
Since Carrie withdraws $10 each day for 7 days, this means that she withdraws a total of
[tex]7\cdot10=70[/tex]so she witdraws $70.
Now we know that each of those days she also deposited $4, the she deposited a total of $28.
The total change in her account in this 7 days woule be $28-$70=-$42.
Second way
Another way to calculate the total change would be like this:
She withdraws $10 dollars each day but she also deposits $4 each day, this means that the change in her account each day will be $4-$10=-$6.
Now, since we know that she did this every day for 7 days the total change in her account would be (7)($-6)=-$42.
