Question 240578
Excluding values means to find the values of x that are NOT allowed.  What is NOT allowed in mathematics is DIVISION BY ZERO.  You will NEVER be allowed to have a denominator equal to zero.


Therefore, you must EXCLUDE the value that makes 7x+21=0
7x=-21
x=-3


This is the EXCLUDED VALUE of X.


Dr. Robert J. Rapalje, Retired
Seminole State College of Florida
Altamonte Springs Campus