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

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:



We can solve by substitution. Let's solve for x in the second equation:


Replace every x in the first equation by that:






Now, plug that in for y in second equation and solve for x:



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.