a farmhouse shelters 11 animals. Some are goats and some are ducks. Altogether there are 34 legs. How many of each animal are there?
There could be lots of answers. I'm going with 5 goats and 7 ducks.
x=goats
y=ducks
4x+2y=34
x+y=11
-y -y
x=11-y
4(11-y)+2y=34
44-4y+2y=34
44-2y=34
-44 -44
-2y=10
/2 /2
y=5
x+y=11
x+5=11
-5 -5
x=6
goats=6
ducks=5