There are a certain amount of Cows and Chickens on a farm. If there are 80 legs and 30 animals (all cows and chickens), how may of each are there?
Cows = x
Chickens = 30 - x
So
4x + 2 [30 - x ] = 80
4x + 60 - 2x = 80 rearrange
2x = 20
x = 10 = Cows
30 - x = 30 - 10 = 20 = Chickens
