Final answer:
To simplify the given rational expression, factor the numerator and denominator and cancel out common factors. The expression is undefined for values that make the denominator zero.
Step-by-step explanation:
To simplify the given rational expression, we need to factor the numerator and the denominator and then cancel out any common factors between them. Let's call the expression f(k) and start by factoring it: f(k) = (k + 10)(k - 10) / (k + 10). Since the (k + 10) terms cancel out, the simplified expression is f(k) = k - 10.
The expression is undefined for values of k that make the denominator zero. In this case, k = -10 makes the denominator zero, so the expression is undefined for k = -10.
So, the answers are: a) Simplified Expression: f(k) = k - 10 b) Undefined for k = 0 c) Undefined for k = 10 d) Undefined for k = -10