When using "the same reason", we must pay attention to the corresponding scope of the same reason, and the conclusion drawn from "the same reason" must be obvious. If the process is complicated, the same principle is not recommended. Many arguments that do not belong to the same reason are included in the solution, which confuses people and affects the quality of the solution. The solution process is also a reflection of your thinking. Generally speaking, only when you are very clear about the whole process, when you organize your solution to the language, using "the same truth" will make the language concise.

In the use of "the same reason", beginners had better put the same reason content at the beginning of the solution, so that all the above contents are the corresponding scope of the same reason, that is, draw the same reason part to the beginning of the solution. It depends on the situation after proficiency.

When using the same reason, remember not to use the same reason, especially when your solution seems short. Because the most complicated proof in middle school is more than 20 lines, short proof basically does not need the same reason.

What you said does not belong to the use of "the same truth". Just say "from the result of the first question …" and you can directly use the conclusion of the first question. Of course, in the process of proving the first question, if only one conclusion is proved in the whole process, it can be said that "from the process of asking the first question, we can draw the same conclusion …". In this way, the process of the first question is different and the conclusion is obvious.