Find all numbers that must be excluded from the domain of each rational expression? 7/x-3

Easy way to do this is to think what number would make the denominator (the bottom half of the fraction) equal to 0.

In other words, what number minus 3 is equal to 0?

Domain is the numbers yo can use

yo can't user numbers that make undefined stuff like sqrt of a negative number or division by 0

assuming

7 / (x-3), find what value is restricted

denomenator cannot be 0

find what makes is 0

x-3=0

x=3

3 must be restricted

if it was (7/x) - 3, then the restricted value would be 0