You make party favors for an event. You tie 9 inches of ribbon around each party favor. Write an expression for the amount of ribbon you need for n party favors. The ribbons cost s $3 for each yard. Write an expression for the total cost of the ribbon.

Need 9n inches of ribbon Cost is $0.75n Since you need 9 inches per party favor and you have n party favors, the amount of ribbon you need is 9 times n inches. So R = 9n inches Since the ribbon costs $3 per yard and our current equation is inches, we need to do a bit of conversion. There's 36 inches per yard and 9 inches per ribbon, so each yard of ribbon can make 36/9 = 4 ribbons for the party favors. So the cost per party favor will be one forth of the cost per yard of ribbon per party favor. So $3.00 / 4 = $0.75, making the cost equation: C = $0.75n