Answer:
There are 15 animals in the field. some are goats and some are ducks. there are 46 legs in all.
How many of each animal are in the field?
Eqn 1 G+D=15
Eqn 2 4G + 2D = 46
Solve Eqn 1 for D
D=15-G
substitute into Eqn 2
4G+ 2(15-G) = 46
4G + 30 – 2G = 46
2G = 16
G= 8
Answer
8 Goats
7 Ducks
