Which of the following is good advice for revising an essay?

-do not let someone else read it too soon; they could interfere with your thinking process.
-read the paper out loud; you might be able to hear mistakes that you would miss if reading it silently.
-keep at least one mistake for the next draft; it will remind you of the way your thought evolved.
-read as quickly as possible because the most important thing is to get to the next step in the writing process.

-Read the paper out loud; you might be able to hear mistakes that you would miss if reading it silently.

Explanation:

When you read the paper outloud you can hear mistakes and phrases that are weirdly constructed becausy you can hear it, plus you pay more attention to a document when you have to read it and pronounce it, than when you are just passing your eyes over it like we tend to do when we read it silently.

substitute y = 2x - 4 to x + 2y = 12:

x + 2(2x - 4) = 12     use distributive property

x + (2)(2x) + () = 12

x + 4x - 8 = 12     add 8 to both sides

5x = 20     divide both sides by 5

x = 4

put the value of x to the first equation:

y = 2(4) - 4

y = 8 - 4

y = 4