Simplify rational expressions: common binomial factors

Problem

Simplify the following rational expression.
start fraction, k, start superscript, 2, end superscript, minus, 22, k, plus, 121, divided by, k, start superscript, 2, end superscript, minus, 121, end fraction, equals
Which values of k make the expression undefined?
Choose all answers that apply:
Choose all answers that apply:
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