Answer:
(a)10x+5y=50
(b)4 $5 bills
(c)3 $10 bills
Step-by-step explanation:
Part A
Given:
The number of $10 bills = x
The number of $5 bills = y
If the total amount of money in his wallet is $50, then:
![10x+5y=50\ldots(1)](https://img.qammunity.org/2023/formulas/mathematics/college/heeblsc869em5zts1bxvs2u4u2lauina2v.png)
Part B
If the number of $10 bills, x = 3
From the equation above:
![\begin{gathered} 10x+5y=50 \\ 10(3)+5y=50 \\ 30+5y=50 \\ 5y=50-30 \\ 5y=20 \\ y=(20)/(5) \\ y=4 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/gdq4fpb2vco9i0koom9709o13rx3a7j0xl.png)
Therefore, if there are 3 $10 bills, there are 4 $5 bills.
Part C
If the number of $5 bills, y=6, then:
![\begin{gathered} 10x+5y=60 \\ 10x+5(6)=60 \\ 10x=60-30 \\ 10x=30 \\ x=(30)/(10) \\ x=3 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/zqjhygtt7fnqtskoi6325b6902ly7pioye.png)
Therefore, if there are 6 $5 bills, there are 3 $10 bills.