What is equivalent expressions by combining terms like 5c - 4c + c

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?

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.

Select the correct answer what is the 10th term of the geometric sequence 3,6, 12, 24,48 a. 512 b. 3,072 c. 768 d. 1,536