With the information provided, you can say that the amount spent in bracelets and necklaces is equal to the price per bracelet for the number of bracelets plus the price per necklace for the number of necklaces, which is:
c=3x+2y, where:
c is the total cost
x is the price per bracelet
y is the price per necklace
Now, you can say that c=21 and x=5 and solve for y to find the price per necklace:
21=(3*5)+2y
21=15+2y
21-15=2y
6=2y
y=6/2
y=3
According to this, the answer is that the cost for 1 necklace is $3.
