Answer:
When x = 4
Step-by-step explanation:
Division by zero is undefined. With real numbers, you are not allowed to divide by zero. Any value of x that causes the denominator to have a value of zero is not allowed. We need to find out which values of x cause the denominator to equal zero.
To do that, we set the denominator equal to zero and solve for x.
2x - 8 = 0
Add 8 to both sides.
2x = 8
Divide both sides by 2.
x = 4
Answer: The rational expression is undefined when x = 4
Check:
Let x = 4, and evaluate the denominator of the fraction.
2x - 8 = 2(4) - 8 = 8 - 8 = 0
By letting x = 4 in the denominator, the denominator does evaluate to zero causing an undefined value in the division. Therefore, our answer above is correct.
