Question 1173484
the total of three sisters ages is 39.
 d + m + j = 39
Dina is half as old as Michelle
 d = .5m
or multiply be 2
 m = 2d
and 3 years younger than Juliette.
 d = j - 3
or Add 3 to both sides
 j = d + 3
how old are the sisters?
Replace m with 2d, replace j with (d+3) in the first equation
d + 2d + (d+3) = 39
4d = 39 - 3
4d = 36
d = 36/4
d = 9 yr is Dina's age
and
2(9) = 18 yrs is Michelle's age
and
9+3 = 12 yrs is Julie's age
:
:
Check: 9 + 18 + 12 = 39