The original formula refers to the original formula, such as 3x+2= 1 1, which is written on the answer sheet during the exam.

So there are two ways to write ① solution: 3x+2= 1 1 ② solution: original formula =3x=9.

3x=9 x=3

x=3

But it's best to write them all in the big exam to prevent him from being in a bad mood and deducting your points.