Question

rational expressions
restriction on a variable in a denominator: linear
find all excluded values for the expression.
that is, find all values of u for which the expression is undefined.
\\(\frac{u - 8}{u - 4}\\)
if there is more than one value, separate them with commas.
\\(u = \\)

Explanation:

Step1: Recall the rule for undefined rational expressions

A rational expression is undefined when its denominator is equal to zero. So, we need to find the value of \( u \) that makes the denominator \( u - 4 \) equal to zero.

Step2: Solve the equation for the denominator

Set the denominator equal to zero: \( u - 4 = 0 \).
To solve for \( u \), add 4 to both sides of the equation: \( u = 4 \).

Answer:

\( u = 4 \)