Hello!
Answer:

Explanation:
→ We want to find how much oil does the tank to be full.
→ We know that:
- The oil tank can hold 4.6 quarts.
- When Sierra checks the tank, it has only 3.25 quarts in it.
→ So the car needs:
quarts more oil to be full.
Conclusion:
Sierra needs to add 1.35 quarts to the tank to make it full.