Which expression is undefined?

Group of answer choices

2 ÷ (−7)

(−7) ÷ 2

0 ÷ -9

-9 ÷ 0

1 answer

The expression that is undefined is \(-9 ÷ 0\). Division by zero is not defined in mathematics, making that expression undefined. The other expressions involve division by non-zero numbers and are therefore well-defined.