Please clarify what exactly is confusing for you in the solution.
What is meant by blank in you question? We understand that blank means unknown which we are asked to find. Is that wrong? Please provide th details so we could help you.
so what is the answer that's every confusing!! all I need to know is what 4/9 dived by blank equals 12. I'm not trying to be rude or mean or anything just that's very confusing.