To represent the inequality, let us define some variables first:
lets say 'w' represents the greatest number of weekly withdrawals:
Elise has budget of $800 in her checking account:
If she withdraws $50 each week then in 'w' number of weeks she has withdrawn
dollars.
The amount left in her checking account is given by:

Now, she needs to have at least $200 available at the end of summer.
Which means:

The inequality
can be used to determine the greatest number of weekly withdrawals.