You have to use general arithmetic rules. If you are not able to work it out then it's best to do it step by step. Remember, if you do one arithmetic operation on one side, it has to be done on the other side.

Multiply Both sides by :

Divide Both sides by :

From here, you are able to substitute your numbers. It's best to re-arrange your formula first before inserting the numbers as if the numbers are decimals or fractions, it can make the re-arrangement more complicated.