题目

Steps to setting your own rules—and keeping them! Google “rules to live by” and you're met with thousands of search results. But how do you know which rules to follow？  16   Fortunately, here is a 3­step process to help you set your own rules. That way, you can actually follow your own advice and do what works for you. Step 1.  17  This can be a goal you want to achieve or a quality you want to own. Once you've decided what you want, you must determine why you want it. Knowing your “why” will take care of your “how”． Step 2.Evaluate what's not currently working.某班共有x个学生，其中女生人数占45%，用代数式表示该班的男生人数是______．