Answer:
12 dozens roses, 6 dozens carnations
Step-by-step explanation:
Let r be every dozen roses and c every dozen carnations.
Then, the price for [tex]r_{n}[/tex] dozens roses will be 23r and the price for [tex]c_{n}[/tex] dozens carnations will be 34c.
So the price for the total of roses and carnations together will be 480:
[tex]23r+34c=480[/tex] (1)
"twice as many roses as carnations" means that if we multiply the quantity of dozens carnations by 2, it will be equal the quantity of dozens roses.
[tex]r=2c[/tex] (2)
then we substitute (2) in (1) as follows:
[tex]23(2c)+34c=480\\46c+34c=480\\80c=480\\c=6[/tex]
If c=6, then r=12 for (2).
Where c and r are the dozens of each flower.