Answer:
Marlina spent $654 on rent.
Explanation:
Let the amount of money Marlina's received for her salary be x.
We know that she spent one-half of her salary on rent and then $338 on her electric and water bill. Therefore, the amount of money she has left can be so far can be represented by:

Next, she spent one-half of what was left on her phone bill. So, we can subtract one-half of the above expression to what we have so far.

Finally, she spent $56 for gas. Thus, we will subtract 56:

And we know that after all of the expenses, she will have $102 left. Therefore:

We want to know how much Marlina spent on rent. So, we can find her salary, since we know the rent is one-half of the salary. To find the salary, we will solve for x.
Distribute:

Rearrange:

Combine like terms:

Add 225 to both sides:

Multiply both sides by 4:

Therefore, Marlina received a total of $1308 for her salary.
We know that she spent half of her salary on rent. Therefore, the amount she spent on rent is:

Marlina spent a total of $654 on rent.