You have the following information given in the problem above:
- She had $421.56 in her checking account.
- She she deposited g $20 bills (which you can rewrite: ) and k quarters (which you can rewrite as folllowing:).
Therefore, the amount of money in her account after the deposit is the sum of the amoun she had in her account plus the amoun of money she deposited.
Then, you can write the following expression:
joby had $421.56 in her checking account when she deposited g $20 bills and k quarters....