Question

find all excluded values for the expression. that is, find all values of y for which the expression is undefined. \\(\frac{y + 4}{y^2 - 8y + 7}\\) if there is more than one value, separate them with commas. \\(y = \square\\)

Explanation:

Step1: Identify undefined condition

A rational expression is undefined when its denominator is zero. So, set the denominator equal to zero: $y^2 - 8y + 7 = 0$.

Step2: Factor the quadratic equation

Factor the quadratic: $y^2 - 8y + 7 = (y - 1)(y - 7) = 0$.

Step3: Solve for y

Set each factor equal to zero:

• For $y - 1 = 0$, we get $y = 1$.
• For $y - 7 = 0$, we get $y = 7$.

Answer:

1, 7