How do you solve this multi step equation?

Question

The ages of three siblings combined is 27. The oldest is twice the age of the youngest. The middle child is 3 years older than the youngest. Write and solve an equation to find the ages of each sibling.

Answer 1

Hi, Yana.

Ok, let's call the ages x,y,z...from youngest to oldest.

z = 2x

y = x + 3

So, we know that x + y + z = 27

Since we can substitute y and z in terms of x using the above equations:

x + (x + 3) + 2x = 27

4x + 3 = 27

4x = 24

x = 6

Now, we know that y = x + 3 = 6 + 3 = 9

z = 2x = 2(6) = 12

Therefore, the ages are 6, 9,12