Rosa saw ducks and cows at a farm. In all, she counted 9 animals and 28 legs. How many ducks and how many cows did she see?

She saw 5 cows and 4 ducks at the farm.

4 ducks and 5 cows

Step-by-step explanation:

Lets assume that there are x number of ducks.

Since there are a total of 9 animals,

then, there must be (9 - x) number of cows.

Each duck has 2 legs and each cow has 4 legs.

So the total number of legs will be 2x + 4 (9 - x).

We are told that there are 28 legs.

Therefore,

2x + 4 (9 - x) = 28

2x + 36 - 4x = 28

- 2x = - 8

x = 4

ducks = 4

cows = 9 - 4 = 5