2. There are 15 animals in the barn. Some are cows and some are roosters. There are 48 legs in
all. Write a system of equations that can be used to determine how many cows and how many
roosters are in the barn.

(9, 6)

Step-by-step explanation:

With 15 animals in total, the equation for the number of animals is

x + y = 15    with x for cows and y for roosters.

With 48 legs in total, the equation for the number of legs is

4x + 2y = 48    with x for cows and y for roosters.  The numbers in front of each variable represent the number of legs each animal has.

Set the first equation equal to y.

y = 15 - x

Substitute this equation into the second equation and solve.

4x + 2y = 48

4x + 2(15 - x) = 48

4x + 30 - 2x = 48

2x + 30 = 48

2x = 18

x = 9

Substitute this value into the first equation and solve.

x + y = 15

9 + y = 15

y = 6

The solution is (9, 6).

they charge the same amount at 20 minutes.

step-by-step explanation: