SOLUTION
Write the information in the question
[tex]\begin{gathered} \text{Total amount in account= \$129} \\ \text{Total amount spend = \$}157 \end{gathered}[/tex]To obtain the balance in the checking account, we subtract
Hence
[tex]\text{ \$129-\$157=-\$28}[/tex]Hence
Mary will be having a new balance of - $28 in her checking account