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 : ![\frac{x}{x-4}=\frac{x}{x-4}+4](https://tex.z-dn.net/?f=%5Cfrac%7Bx%7D%7Bx-4%7D%3D%5Cfrac%7Bx%7D%7Bx-4%7D%2B4)
Now, solved the rational expression and check its proposed solution
![\frac{x}{x-4}=\frac{x}{x-4}+4](https://tex.z-dn.net/?f=%5Cfrac%7Bx%7D%7Bx-4%7D%3D%5Cfrac%7Bx%7D%7Bx-4%7D%2B4)
x cannot equal to 4, as it makes both denominators equal to zero.
Multiply both the sides by (x-4),
![\left ( x-4 \right )\cdot \frac{x}{x-4}=\left (x-4 \right )\cdot\left ( \frac{x}{x-4}+4 \right )\\](https://tex.z-dn.net/?f=%5Cleft%20%28%20x-4%20%5Cright%20%29%5Ccdot%20%5Cfrac%7Bx%7D%7Bx-4%7D%3D%5Cleft%20%28x-4%20%5Cright%20%29%5Ccdot%5Cleft%20%28%20%5Cfrac%7Bx%7D%7Bx-4%7D%2B4%20%20%5Cright%20%29%5C%5C)
Now, use the distributive property on Right hand side,
![\left ( x-4 \right )\cdot \frac{x}{x-4}=\left (x-4 \right )\cdot \left ( \frac{x}{x-4} \right )+\left (x-4 \right )\cdot 4\\](https://tex.z-dn.net/?f=%5Cleft%20%28%20x-4%20%5Cright%20%29%5Ccdot%20%5Cfrac%7Bx%7D%7Bx-4%7D%3D%5Cleft%20%28x-4%20%5Cright%20%29%5Ccdot%20%5Cleft%20%28%20%5Cfrac%7Bx%7D%7Bx-4%7D%20%5Cright%20%29%2B%5Cleft%20%28x-4%20%5Cright%20%29%5Ccdot%204%5C%5C)
Simplify the above expression,
![x=x+4x-16](https://tex.z-dn.net/?f=x%3Dx%2B4x-16)
Combine like terms,
![x-x-4x=-16](https://tex.z-dn.net/?f=x-x-4x%3D-16)
![-4x=-16](https://tex.z-dn.net/?f=-4x%3D-16)
Divide both sides by -4, we get
![\frac{-4x}{-4}=\frac{-16}{-4}](https://tex.z-dn.net/?f=%5Cfrac%7B-4x%7D%7B-4%7D%3D%5Cfrac%7B-16%7D%7B-4%7D)
.
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: ![\frac{x}{x-4}=\frac{x}{x-4}+4](https://tex.z-dn.net/?f=%5Cfrac%7Bx%7D%7Bx-4%7D%3D%5Cfrac%7Bx%7D%7Bx-4%7D%2B4)
Substitute the value of <em>x</em>=4 in the original expression,
![\frac{4}{4-4}=\frac{4}{4-4}+4](https://tex.z-dn.net/?f=%5Cfrac%7B4%7D%7B4-4%7D%3D%5Cfrac%7B4%7D%7B4-4%7D%2B4)
![\frac{4}{0}=\frac{4}{0}+4](https://tex.z-dn.net/?f=%5Cfrac%7B4%7D%7B0%7D%3D%5Cfrac%7B4%7D%7B0%7D%2B4)
Thus, 4 must be rejected as the solution, and the solution set is only 0.