SOLUTION: Ama's age is two thirds that of her sister. four years ago Ama's age was half the sister. how old is the sister

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Question 1091694: Ama's age is two thirds that of her sister. four years ago Ama's age was half the sister. how old is the sister

Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Ama's age is two thirds that of her sister.
four years ago Ama's age was half the sister.
how old is the sister
:
let a = A's age
let s = sis's age
:
Write an equation for each statement
Ama's age is two thirds that of her sister.
a = 2%2F3s
:
four years ago Ama's age was half the sister.
a - 4 = 1%2F2(s-4)
Multiply both sides by 2
2(a-4) = s - 4
2a - 8 = s - 4
2a = s - 4 + 8
2a = s + 4
replace a with 2%2F3s
2(2%2F3s) = s + 4
4%2F3s = s + 4
multiply both sides by 3, get rid of the annoying fraction
4s = 3(s+4)
4s = 3s + 12
4s - 3s = 12
s = 12 yrs is the sister's age
:
;
you should find a and then check the solutions in the 2nd statement