You buy $52 worth of flowers. You buy 12 flowers. Calla lillies cost $3,50 each and peonies cost $5,50 each. How many calla lilles and peonies did you buy?

Question

Just an Algebra review. I am not sure how to set this up.

Answer 1

Well, let's look at what you know:

 

We know that you spent a total of $52.00

We know that you bought a combination of Call lillies and peonies and so:

 

We could let x represent the # of Calla lillies that you bought, and we know that they cost $3.50 each

 

We could let y represent the # of Peonies that you bought, and we know that they cost $5.50 each, 

 

so now, we have 2 variables and 2 equations, so we can say:

 

x + y = 12 and

$3.50x + $5.50y = $52

 

Now we need to solve for one variable, so we could express y in terms of x:

 

Using our first equations:

 

x + y = 12

 

we can subtract x from both sides

 

x-x + y = 12 - x

 

leaving:

 

y = 12 - x

 

So now we can substitute 12 - x in the second equations and solve for x:

 

$3.50x + $5.50 (12-x) = $52

 

3.50 x + 66 - 5.50x = 52

66-2x= 52

66-66-2x= 52-66

-2x = -14

2x = 14

x = 7

 

y = 12 - x 

y = 12 - 7 = 5

 

Hence, you bought 7 calla lillies and 5 peonies!

 

Check:

 

3.50 (7) + 5.50 (5) = 24.50 + 27.50 = 52

 

I hope that this helps!