How to solve linear equations

i found this on google:

Step-by-step explanation:

To solve linear equations we will make heavy use of the following facts. If a=b then a+c= b+c a + c = b + c for any c . All this is saying is that we can add a number, c , to both sides of the equation and not change the equation. If a=b then a−c=b−c a − c = b − c for any c

i think asking google will you get the answer to that question