Braulio and Alejandro are siblings. Three years from now, Braulio will be 3 times Alejandro's present age. At that time, Alejandro will then be half as old as Braulio. How old are Braulio and Alejandro? Show all work and circle your final answers

Braulio is 15 years old, and Alejandro is 6 years old.

Step-by-step explanation:

Let's define:

B = Age of Braulio

A = Age of Alejandro.

"Three years from now, Braulio will be 3 times Alejandro's present age"

We can write this as:

B + 3 = 3*A

"At that time, Alejandro will then be half as old as Braulio"

A + 3 = (B + 3)/2

Then we have a system of equations:

B + 3 = 3*A

A + 3 = (B + 3)/2

To solve this, we first need to isolate one of the variables in one of the equations.

Let's isolate A in the second equation:

A = (B + 3)/2 - 3

Now we can replace this in the other equation to get:

B + 3 = 3*A

B + 3 = 3*((B + 3)/2 - 3)

B + 3 = (3/2)*B + 9/2 - 9

Now let´s move all the terms with B to the left side, and the other terms to the right side.

B - (3/2)*B = 9/2 - 9 - 3

-(1/2)*B = 9/2 - 18/2 - 6/2 = -15/2

B = (-2)*(-15/2) = 15

Braulio is 15 years old.

And from the first equation:

B + 3 = 3*A

15 + 3 = 3*A

18 = 3*A

18/3 = A = 6

Alejandro is 6 years old.

17 1/3

step-by-step explanation: