Antonio's checking account currently has a negative balance of - $42.17. Yesterday he made purchases of $3.75 and $12.07. If Antonio's bank charges $34 for overdraft protection, what was his account balance prior to yesterday's transactions?

He started the day with 7.65

Step-by-step explanation:

Assuming at the beginning of yesterday he had a balance of x

He will be charged 34 dollars since he went negative

x - 3.75 - 12.07 - 34 = -42.17

Combine like terms

x - 49.82 = - 42.17

Add 49.82 to each side

x - 49.82+49.82 = - 42.17+49.82

x = 7.65