What is negative 8 plus 8

Need on this one asap im almost done with this subject

Janie has $3. she earns $1.20 for each chore she does and can do fractions of chores. she wants to earn enough money to buy a cd for $13.50. write an inequality to determine the number of chores, c, janie could do to have enough money to buy the cd.

Acabinmaker buys 3.5 liters of oat varnish the varnish cost $4.95 per liter what is the total cost of 3.5 liters