Respuesta :
Answer:
21 birds.
Step-by-step explanation:
Let B represent the number of birds and C represent the number of cats.
We have been given that an animal shelter spends $1.50 per day to care for each bird, so the amount spent on B birds will be 1.50B.
The animal shelter spends $8.50 per day to care for each cat, so the amount spent on C cats will be 8.50C.
Alexander noticed that the shelter spent $108.00 caring for birds and cats on Tuesday. We can represent this information in an equation as:
[tex]1.50B+8.50C=108...(1)[/tex]
Alexander found a record showing that there were a total of 30 birds and cats on Tuesday. We can represent this information in an equation as:
[tex]B+C=30...(2)[/tex]
We will use substitution method to solve system of linear equations.
From equation (2) we will get,
[tex]C=30-B[/tex]
Substituting this value in equation (1) we will get,
[tex]1.50B+8.50(30-B)=108[/tex]
[tex]1.50B+255-8.50B=108[/tex]
[tex]255-7B=108[/tex]
Let us subtract 255 from both sides of our equation.
[tex]255-255+7C=108-255[/tex]
[tex]-7B=-147[/tex]
Let us divide both sides of our equation by -7.
[tex]\frac{-7B}{-7}=\frac{-147}{-7}[/tex]
[tex]B=21[/tex]
Therefore, there were 21 birds at the shelter on Tuesday.
