The rational number with square 81 is______ The number whose reciprocal equals itself is____ . In: - (- 5), - (- 5) & sup2;, - | - 5 |, (- 5) & sup3;. How many negative numbers are there? Please indicate which ones are negative

The rational number with square 81 is______ The number whose reciprocal equals itself is____ . In: - (- 5), - (- 5) & sup2;, - | - 5 |, (- 5) & sup3;. How many negative numbers are there? Please indicate which ones are negative

The rational number whose square is 81 is ± 9, and the number whose reciprocal equals itself is ± 1