Answer:
Any proposed solution of a rational equation that causes a denominator to equal __ZERO__ is rejected.
Step-by-step explanation:
We will show this statement is true by an example:
Consider the expression : 
Now, solved the rational expression and check its proposed solution

x cannot equal to 4, as it makes both denominators equal to zero.
Multiply both the sides by (x-4),

Now, use the distributive property on Right hand side,

Simplify the above expression,

Combine like terms,


Divide both sides by -4, we get

.
As we know that x cannot equal to 4, replacing x=4 in the original expression causes the denominator equal to 0.
Check the solution: 
Substitute the value of <em>x</em>=4 in the original expression,


Thus, 4 must be rejected as the solution, and the solution set is only 0.