A dog that weighs 20 pounds on Earth weighs 7.6 pounds on Mars. A cat that weighs 15 pounds on Earth weighs x pounds on Mars.

If the unit rate remains the same, what is the value of x?

Since the dog weighs 20 pounds on Earth and 7.6 pounds on Mars, we need to subtract 7.6 from 20. So 20-7.6 = 12.4. So there is a change of 12.4

Now we need to subtract 12.4 from 15 and we get 2.6

So the cat weighs 2.6 pounds on Mars.