Answer :
9
0.5 means you can write the problem out like this 1/(81)^(1/2)=1/9
meaning 1 part of 81 would be 9
9x9 = 81
0.5 means you can write the problem out like this 1/(81)^(1/2)=1/9
meaning 1 part of 81 would be 9
9x9 = 81