Question 99603
A wholesaler is offering two different package deals of roses and carnations to florists. One package contains 20 dozen roses and 34 dozen carnations for $504.00. The other package contains 15 dozen roses and 17 dozen carnations for $327.00. 

Let x = cost of one dozen roses 

Let y = cost of one dozen carnations 

a. Write a system of equations for this problem. 
1st; 20x+34y= 504
2nd: 15x+17y=327


b. Which equation can be multiplied by a coefficient to create an opposite coefficient? 2nd is the best choice
What is that value? -2

c. Solve this system for the cost of one dozen roses and the cost of one dozen carnations.
1st:  20x+34y=504
3rd: -30x-34y=-654
--------
Add 1st and 3rd to get:
-10x = -150
x = 15 (# of dozens of roses)
-------------
Substitute into 20x+34y=504 ot solve for y:
20*15+34y = 504
300 + 34y = 504
34y = 204
y = 6 (# of dozens of carnations)
===============
Cheers,
Stan H.