SOLUTION: Eight roses and 9 carnations cost $3.35. At the same prices, one dozen roses and 5 carnations cost $3,75. Find the cost of a rose and the cost of a carnation.

Algebra ->  College  -> Linear Algebra -> SOLUTION: Eight roses and 9 carnations cost $3.35. At the same prices, one dozen roses and 5 carnations cost $3,75. Find the cost of a rose and the cost of a carnation.      Log On


   



Question 1010510: Eight roses and 9 carnations cost $3.35. At the same prices, one dozen roses and 5 carnations cost $3,75. Find the cost of a rose and the cost of a carnation.
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
Call their prices, r and c. Then we have
8r + 9c = 335 (work in cents) and
12r + 5c = 375
Now multiply the top one by 3 and the bottom by 2 and subtract them...we get...
24r + 27c = 1005
-(24r + 10c = 750)
-------------------
17c = 255
c = 15 cents per carnation
so that
8r + 9(15) = 335
8r + 135 = 335
8r = 200
r = 25 cents per rose