EXPLANATION :
From the problem, the cost of a bracelet is $3 and a necklace is $6
We need the cost of bracelets and necklaces for 0, 1, 2, 3, and 4 pieces of jewelry.
Since the bracelet costs $3, we can represent the total cost as 3n, where n = 0, 1, 2, 3, and 4
![\begin{gathered} n=0\rightarrow3(0)=\$0 \\ n=1\rightarrow3(1)=\$3 \\ n=2\operatorname{\rightarrow}3(2)=\operatorname{\$}6 \\ n=3\operatorname{\rightarrow}3(3)=\operatorname{\$}9 \\ n=4\operatorname{\rightarrow}3(4)=\operatorname{\$}12 \end{gathered}]()
The first column will be 0, 3, 6, 9, and 12
For the necklace with a cost of $6, we can represent the total cost as 6n, where n = 0, 2, 3, and 4.
![\begin{gathered} n=0\rightarrow6(0)=\$0 \\ n=1\operatorname{\rightarrow}6(1)=\operatorname{\$}6 \\ n=2\operatorname{\rightarrow}6(2)=\operatorname{\$}12 \\ n=3\operatorname{\rightarrow}*6(3)=\operatorname{\$}18 \\ n=4\operatorname{\rightarrow}*6(4)=\operatorname{\$}24 \end{gathered}]()
The second column will be 0, 6, 12, 18, and 24
For the third column, we can write the cost of bracelets and necklaces as an ordered pair (bracelet, necklace)
So we have (0, 0), (3, 6), (6, 12), (9, 18), and (12, 24)
Plot these points to the rectangular coordinate system :
Relationship between the cost of bracelets and necklaces :
With the same number of jewelry, the cost of necklaces is twice the cost of bracelets.