Barb had $112 in her savings account. then deposited the same amount of money into her savings account in the next 4 months. now she has $333 in her savings account. how much money, m, did barb deposit each month?

You don't mention interest, so I'll need to assume that interest calculations are not part of the picture here.  Barb now has $333; at the beginning she had $112.  That means that over four months she deposited $221. 

That comes to $221/4 per month, or $55.25.

I’m vary good with science if you need with that