I told you what to do. Most examples in FAA exams are old and out of date. Much more simple and practical ways of obtaining W & B and performance numbers are used today in the "real world". So, knock yourself out and take 3 hours to complete your ATP written by doing all those long hand archaic calculations. Or, just memorize the answers, get the test done in 28 minuets and score a 98%. As long as you know how to do the calculations and understand them, that's all that matters.