An animal shelter spends $4.50 per day to care for each bird and $8.50 per day to care for each cat. Joshua noticed that the shelter spent $173.50 caring for birds and cats on Tuesday. Joshua found a record showing that there were a total of 27 birds and cats on Tuesday. How many birds were at the shelter on Tuesday?

76 birds

Step-by-step explanation:

Let x = the number of birds

Let y = the number of cats

x + y = 35       y = 35 - x

4.50x + 8.50y = 221.50       Multiply the whole equation by 100.

450x + 850y = 22150

450x + 850(35 - x) = 22150

450x + 29750 - 850x = 22150

-100x = -7600

x = 76 birds

add all the numbers and check the ones place.

the answer is 486. as the ones place is more than 4, the estimation will be the next 10 ie, 490