Question 949379
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