Question

square root 9 +square root 81=?

Answer 1

√9+√81
=3+9=12
the answer is 12

Answer 2

= √9 + √81    or    = √9 + √81

= 3 + 9                   = -3 + ( - 9 )

= 12.                      = -3 -9
                              = -12

So, answer is either 12 or -12.