Question 73087
<pre>

          {{{sqrt(x-1) = 3}}}

          {{{(sqrt(x-1))^2}}} = {{{3^2}}}

                    x - 1 = 9
                        x = 9 + 1
                        x = 10

Checking:

  {{{sqrt(x-1) = 3}}}, x = 10

  {{{sqrt(10-1) = 3}}}

  {{{sqrt(9) = 3}}}

         3 = 3 --------------> True

Therefore x = 10