Please answer correctly !!!!!!!!!! Will mark brainliest !!!!!!!!!!!!

Answer:
11.5 years old
Step-by-step explanation:
Let's call Michael's current age m, and Brandon's current age b.
m=3b
m-18=9(b-9)
Substituting:
3b-18=9(b-9)
3b-18=9b-81
6b=63
b=11.5
Hope this helps!