SOLUTION: Lizzys brother is 4 times older than her. Six years later, her brother was only twice as old as she was then. How old are they now?

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Question 991671: Lizzys brother is 4 times older than her. Six years later, her brother was only twice as old as she was then. How old are they now?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
let b = brother's age
let z = Liz's age
:
write an equation for each statment
:
Lizzy's brother is 4 times older than her.
b = 4z
Six years later, her brother was only twice as old as she was then.
b + 6 = 2(z + 6)
b + 6 = 2z + 12
b = 2z + 12 - 6
b = 2z + 6
replace b with 4z
4z = 2z + 6
4z - 2z = 6
2z = 6
z =6/2
z = 3 yrs is Liz's age
then
4(3) = 12 yrs is brother's age
:
:
you can confirm this by using these ages in the 2nd statement