Question 949379:  Show your method used to solve problem. 
If the cost of 5 roses, 9 irises and 6 carnations is the same as 3 carnations 6 irises and 8 roses find the cost of a single iris if it cost $42 for a dozen roses and a carnation is three-quarters the cost of an iris.  
 Found 3 solutions by  macston, MathTherapy, lwsshak3: Answer by macston(5194)      (Show Source): 
You can  put this solution on YOUR website! I=cost of iris; C=cost of carnation=0.75I; R=cost of rose=$42/12=$3.50 
5R+9I+6C=3C+6I+8R Substitute for C and R. 
5($3.5)+9I+6(0.75I)=3(0.75I)+6I+8($3.5) 
$17.50+9I+$4.50I=2.25I+6I+$28.00 Subtract $17.50 from each side. 
$13.50I=$8.25I+$10.50 Subtract $8.25I from each side. 
$5.25I=$10.50 Divide each side by $5.25. 
I=$2.00 ANSWER: An iris costs $2.00. 
CHECK: 
C=0.75I=0.75($2)=$1.50 A carnation costs $1.50. 
5R+9I+6C=3C+6I+8R 
5($3.50)+9($2.00)+6($1.50)=3($1.50)+6($2.00)+8($3.50) 
$17.50+$18.00+$9.00=$4.50+$12.00+$28.00 
$44.50=$44.50 
 
 Answer by MathTherapy(10557)      (Show Source): 
You can  put this solution on YOUR website!  
Show your method used to solve problem. 
If the cost of 5 roses, 9 irises and 6 carnations is the same as 3 carnations 6 irises and 8 roses find the cost of a single iris if it cost $42 for a dozen roses and a carnation is three-quarters the cost of an iris.  
 
Let price of 1 rose, 1 iris and 1 carnation be R, I, and C, respectively 
Then we can say that: 5R + 9I + 6C = 8R + 6I + 3C  
8R - 5R + 6I - 9I + 3C - 6C = 0 
3R  - 3I - 3C = 0 
3(R - I - C) = 3(0) ------ Factoring out GCF, 3 
R - I - C = 0 ------- eq (i)
 
12R = 42 
R, or cost of 1 rose =  , or $3.50
 
 _____  ------- Cost of 1 carnation is   cost of an iris 
 
R - I - C = 0 -------- eq (i) 
 -------- Substituting 3.5 for R, and   for C in eq (i) 
  -------- Multiplying by LCD, 4 
14 - 7I = 0 
14 = 7I  
Cost of 1 iris =  , or    
 Answer by lwsshak3(11628)      (Show Source): 
You can  put this solution on YOUR website! Show your method used to solve problem. 
If the cost of 5 roses, 9 irises and 6 carnations is the same as 3 carnations 6 irises and 8 roses find the cost of a single iris if it cost $42 for a dozen roses and a carnation is three-quarters the cost of an iris. 
*** 
let r=cost/rose=42/12 
let i=cost/iris 
let c=cost/carnation=(3/4)i 
.. 
5r+9i+6c=3c+6i+8r 
5(42/12)+9i+6(3/4)i=3(3/4)i+6i+8(42/12) 
210/12+9i+(18/4)i=(9/4)i+6i+336/12 
lcd:12 
210+108i+54i=27i+72i+336 
63i=126 
i=2 
cost of a single iris=$2 
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