Question

An animal shelter spends $2.50 per day to care for each bird and $3.00

per day to care for each cat. Isabella noticed that the shelter spent $80.00 caring for birds and cats on Thursday. Isabella found a record showing that there were a total of 28 birds and cats on Thursday. How many birds were at the shelter on Thursday?

Answer 1

8 birds

Explanation:

let b = number of birds

c = number of cats

b + c = 28 eq.1

2.5b + 3c = 80 eq.2

multiply eq.1 by -3

-3b - 3c = -84 eq.3

add eq.2 and eq.3

2.5b + 3c = 80

-3b - 3c = -84

____________

-0.5b = -4

b = 8