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.

answer: true

step-by-step explanation:

54 kilometers per hour

step-by-step explanation:

according to rules:

1 km = 1000 meter

which means that 1 meter = 1/1000 km

1 hour = 3600 second [ as 1 hour = 60 min = 60 *60 seconds ]

which means that 1 second = 1/3600 hour

therefore, 1 kilometer/hour =

thus to convert 15 meter per second to kilometer per hour, we multiply 15 to 3.6 kilometer/hour.

15 meter/second=   which is the required answer.