The expression shown in the image is:

$\sqrt{3 \sqrt{9 \sqrt{27}}}$

To solve this step by step:

1. Innermost square root: $\sqrt{27} = \sqrt{9 \times 3} = \sqrt{9} \times \sqrt{3} = 3\sqrt{3}$

2. Next square root: Now substitute $\sqrt{27} = 3\sqrt{3}$ into the expression: $\sqrt{9 \sqrt{27}} = \sqrt{9 \times 3\sqrt{3}} = \sqrt{27\sqrt{3}}$

   This is a bit more complicated. Let's approximate or simplify further:

   • We can estimate $\sqrt{27\sqrt{3}}$, but it doesn't simplify easily in exact terms without a numerical approach.

Would you like to approximate numerically, or keep it in symbolic form?