Answer:
[tex] -12 [/tex]
Step-by-step explanation:
You start with 87 dollars.
[tex] 87 [/tex]
You write a check for 99 dollars.
Writing a check means taking money out of the bank.
[tex] 87 - 99 [/tex]
[tex] -12 [/tex]
She will have -12 dollars.
She is in debt for 12 dollars.
She owes the bank 12 dollars.