algebraic expression

Question

Bob sells orchids and lillies. He sells a dozen orchids for $50 and a dozen lillies for $20. Last week he sold 15 dozen of the two types of flowers for a total of $450. How many dozen did he sell of each?

Answer 1

Let,

x= dozens of orchids

y= dozens of lillies

 

Therefore,

x+y=15

and 

50x+20y=450

 

 

Solve for y in the first equation so that you can use that to solve for x in the second equation.

y=15-x

 

Substitute y with 15-x in the second equation to solve for x

50x + 20(15-x) = 450

50x + 300 - 20x = 450

30x = 150

x= 5

 

Now that you know x, solve for y

5 + y = 15

y= 10

 

Check your answer:

50(5) + 20(10) = 450

250 + 200 = 450