Question

There are 52 birds and acts in the store. For the same animals Kia counts 138 legs. How many birds and cats are in the pet store

Answer 1

Let's represent birds by the letter x and cats by the letter y. Since birds have 2 legs, and cats have 4, we can express this as:
$138 = 2x + 4y$
$52 = x+y$

We can solve by substitution. Let's solve for x in the second equation:
$x = 52-y$

Replace every x in the first equation by that:
$138 = 2(52-y)+4y$
$138 = 104-2y+4y$
$138 = 104 + 2y$
$34 = 2y$
$y = 17$

Now, plug that in for y in second equation and solve for x:
$52 = x + 17$
$x = 35$

Since x was the number of birds and y was the number of cats in the store, there are 35 birds and 17 cats in the store.