An animal shelter spends $2.50 per day to care for each bird and $7.50 per day to care for each cat. Allison noticed that the sh
elter spent $62.50 caring for birds and cats on Monday. Allison found a record showing that there were a total of 19 birds and cats on Monday. How many birds were at the shelter on Monday?
1. Write out your equations X = birds Y= cats x + y = 19 2.50x + 7.50y = 62.50
2. Isolate one variable. x + y = 19 x = 19 - y
3. Plug this in as the variable in the other equation. Then, solve. 2.5(19 - y) + 7.5y = 62.5 47.5 - 2.5y + 7.5y = 62.5 -2.5y + 7.5y = 15 5y = 15 y = 3 (cats)
4. Solve for the other variable. We know there were 19 animals in total on Monday. Since there were 3 cats, there must be 16 birds.
5. Double check by plugging the numbers into the original equations. 16 + 3 = 19 19 = 19 (true)
