In which cases do we need to check whether x values found holds true or not?
Like in this question, we got x= 1 and x= -3/5. We later had to check both the values whether it satisfies the absolute equation x+3 =4x or not.

In what questions or cases - do we need to do this checking of x values?

In which cases do we need to check whether x values found holds true or not?
Like in this question, we got x= 1 and x= -3/5. We later had to check both the values whether it satisfies the absolute equation x+3 =4x or not.

In what questions or cases - do we need to do this checking of x values?