Answer:
Barry has 15 dollars, Sherry 35 dollars and Perry 70 dollars.
Step-by-step explanation:
Let's start by setting Sherry's cash as a variable named x, Barry's cash named as y and Perry's cash named as z.
The 3 children together have 120$, meaning that the following equation is true:
[tex]x + y + z = 120[/tex]
If Barry (y) has 20$ less than Sherry (x), then we can conclude, that:
[tex]y = x - 20[/tex]
If Perry (z) has 2 times the amount of money Sherry (x) has, then we can conclude, that:
[tex]z = 2x[/tex]
If we replace all the y and z variable in the first equation with what we just made, we get a way easier equation than before:
[tex]x + (x - 20) + (2x) = 120[/tex]
We can easily remove the brackets and go on to solving the equation, giving us x, which is equal to how much money Sherry has:
[tex]x + x - 20 + 2x = 120 \\ 4x - 20 = 120 \\ 4x = 140 \\ x = 35[/tex]
So, Sherry has 35$. Since Barry has 20$ less than 35$, we can conclude, that:
[tex]35 - 20 = 15[/tex]
Barry has 15$.
If Perry has 2 times the amount Sherry has, then we can conclude, that:
[tex]2 \times 35 = 70[/tex]
Perry has 70$.
