Jack brought 3 slices of cheese pizza and 4 slices of mushroom pizza for total cost of $12.50. Grace brought 3 slices of cheese pizza and 2 slices of mushroom pizza for total coast of $8.50. The system of equations below represents these facts

When rates are expressed as a quantity of 1, such as 2 feet per second or 5 miles per hour, they are called unit rates. if you have a multiple-unit rate such as 120 students for every 3 buses, and want to find the single-unit rate, write a ratio equal to the multiple-unit rate with 1 as the second term.

The answer is 1 because you have to flip the sign when dividing by negative number and 3