Question

Brianne is three times as old as Camila. Four years from now she will be two-times as old as Camila. How old are Brianne and Camila now?

Answer 1

b=brianne present age
c=camila present age

b=3c    (brianne is three times as old as camila)

b+4=2(c+4)     (four years from now she will be two times as old as Camila)

b + 4 = 2c + 8
b = 2c + 8 - 4
b = 2c + 4
Replace b with 3c
3c = 2c + 4
3c - 2c = 4
c = 4 

Camila is four years old. 

b+4=2c+8
b=2(4)+4
b=8+4
b=12
Brianne is 12 years old. 

Answer 2

Answer:

Age of Camila is: 4 years.

Age of Brianne is: 12 years.

Step-by-step explanation:

Let the present age of Camila be : x

and the present age of Brianne be : 3x.

( Since, it was given that:

Brianne is three times as old as Camila )

Four years from now the age of Camila will be:  x+4

and the age of Brianne will be: 3x+4

Now, it is given that:

Four years from now she will be two-times as old as Camila.

i.e.

$3x+4=2(x+4)\\\\i.e.\\\\3x+4=2x+2\times 4\\\\3x+4=2x+8\\\\3x-2x=8-4\\\\x=4$

Hence, the age of Camila is: 4 years.

and the age of Brianne is: 12 years.