Question

5 square root of 40?

Answer 1

This simply means 5 multiplied by whatever the value of the squared root of 40 is.

Answer 2

.. 5(6.32)= approx 31.6

Answer 3

is that what you wanted?

Answer 4

Or perhaps this:
\[5\sqrt{40}=5\sqrt{5*2*2*2}=5\left(2 \sqrt{10}\right)=10 \sqrt{10} \]