Jessie has some chickens and rabbits. there are 30 heads and 76 legs in all. How many chickens and rabbits does jessie have?
Let c = number of chickens and r = number of rabbits.
Number of heads equation: c + r = 30 ---> multiply by 4 ---> 4c + 4r = 120
Number of legs equation: 2c + 4r = 76 ---> multiply by -1 ---> -2c - 4r = -76
Add down the columns: 2c = 44
c = 22
r = 8
