A roller coaster has 4 cars, each with the same number of seats. There are 21 passengers seated in the roller coaster, but 3 seats are empty. Write an equation that can be used to determine the number of seats in each car, s. I appreciate any help!

The fence around a quadrilateral-shaped pasture is 3a^2+15a+9 long. three sides of the fence have the following lengths: 5a, 10a-2, a^2-7. what is the length of the fourth side of the fence?

Merrida uses a pattern in the multiplication table below to find ratios that are equivalent to 7: 9. if merrida multiplies the first term, 7, by a factor of 6, what should she do to find the other term for the equivalent ratio? multiply 9 by 1. multiply 9 by 6. multiply 9 by 7. multiply 9 by 9.

Find the distance between c and d on the number line c=3 and d=11