How can you apply the remainder theorom

In remainder theorem, first we set the given factor or the divisor to 0 and solve for the variable. Then we put the value of the vriable that we got on setting the divisor to 0, in the given polynomial and check the result . If the result is 0, then the given divisor is a factor, else it is not. For e.g. Suppose we have to see whether x-1 is a factor of x square -2x+1 or not. So we set x-1to 0 that is x-1=0 which gives x=1 . Now we put 1 for x in x square -2x+1 that is 1-2+1 =0, so x-1 is a factor of the given polynomial .