Let Briana be x years old.
Thus, Carlee is x + 4 years old and Dauna is x + 7 years old.
A)
Since their total age is 44, we have:
x + (x + 4) + (x + 7) = 44
B)
x + (x + 4) + (x + 7) = 44
3x + 11 = 44
3x = 33
x = 33 / 3
x = 11
C)
x = 11
x + 4 = 11 + 4 = 15
x + 7 = 11 + 7 = 18
Hence, Briana is 11 years old, Carlee is 15 years old and Dauna is 18 years old.