Answer:
9 years old is Brandon
Explanation:
Let M represents the Michael and B represents the Brandon.
As per the given statement: Michael is 4 times as old as Brandon.
⇒
.....[1]
Also, it is given that Michael is 27 years older than Brandon.
⇒
.....[2]
Substitute equation [1] into [2] we get;

Subtract B from both sides we get;
3B = 27
Divide both sides by 3 we get;
B = 9 years
Therefore, the Brandon is 9 years old.