Answer:
He saw 1 duck and 3 dogs.
Explanation:
Given:
Evan went to the park and saw four animals.
Each animal was either a duck or a dog.
He saw a total of 14 legs.
Now, to find the number of each animal he had seen.
Let the number of duck be

And the number of dog be

So, total number of animals:
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Now, the total number of legs he did see:
As we know the legs of a duck are 2 and a dog are 4.
Adding both sides by -16 we get:

Dividing both sides by -2 we get:

The number of duck = 1.
Now, putting the value of
in above equation we get:


The number of dogs = 3.
Therefore, he saw 1 duck and 3 dogs.