First of all, you should understand that the theoretical basis of the shift term of the equation is the nature of the equation, that is to say, as long as you understand the nature of the equation, the problem you mentioned will be self-defeating.

The expression of equality is called equality.

The equation has three properties:

Property 1: both sides of the equation are added with the same number or formula at the same time, and the two sides are still equal.

If a=b

Then there is a+c = b+C.

Property 2: Both sides of the equation are multiplied (or divided) by the same non-zero number or formula at the same time, and the two sides are still equal.

If a=b

Then there is a c = b c

Or a \c = b \c(a, b≠0 or a=b, c≠0).

Property 3: Both sides of the equation are multiplied (or squared) at the same time, and both sides are still equal.

If a=b

Then there is a c = b C

Or (radical c a) = (radical c b)

Look at the textbook again, hoping I can find the answer.