64.7k views
3 votes
An animal shelter spends $2.50 per day to care for each bird and $4.00 per day to care for each cat. Evelyn noticed that the shelter spent $123.50 caring for birds and cats on Thursday. Evelyn found a record showing that there were a total of 35 birds and cats on Thursday. How many birds were at the shelter on Thursday?

A) 15 birds
B) 20 birds
C) 25 birds
D) 30 birds

User David Hay
by
7.2k points

2 Answers

1 vote

Answer:

x= birds

y = cats

. Evelyn found a register showing a total of 35 birds and cats on Thursday--->x+y=35

An animal shelter spends $2.50 per day to care for each bird and $4.00 per day to care for each cat. Evelyne noticed that the shelter spent $123.50 to care for the birds and cats on Thursday--->

2.5x+4y=$123.50

system to solve

x+y=35

2.5x+4y=123.5

by substitution: x= 35-y

replace x :

2.5(35-y)+4y=123.5

87.5-2.5y+4y=123.5

1.5y=123.5-87.5

1.5y=36

y=24

on thursday there were 24 cats

we calculate x:

x+y=35

x+24=35

x=35-24

x=11

on Thursday there were 11 birds

User Zachzurn
by
7.3k points
2 votes

Final answer:

To find the number of birds at the shelter on Thursday, solve the system of equations. The number of birds is 11.

Step-by-step explanation:

To find the number of birds at the shelter on Thursday, we can set up a system of equations. Let's say x represents the number of birds and y represents the number of cats. From the given information, we know that the shelter spent $2.50x caring for birds and $4.00y caring for cats. We also know that the total amount spent on Thursday was $123.50. So we can write the equation: 2.50x + 4.00y = 123.50

We also know that the total number of birds and cats is 35. So we can write another equation: x + y = 35

We can solve this system of equations using substitution or elimination. Let's use elimination. Multiply the second equation by -2.50 to get: -2.50x - 2.50y = -87.50

Add this equation to the first equation: (2.50x + 4.00y) + (-2.50x - 2.50y) = 123.50 + (-87.50)

Simplify the equation: 1.50y = 36

Divide both sides by 1.50: y = 24

Substitute y = 24 into the second equation: x + 24 = 35

Subtract 24 from both sides: x = 11

Therefore, there were 11 birds at the shelter on Thursday.

User Ivanka Todorova
by
7.2k points