Use BODMAS or BIDMAS (Brackets, over Indices, Division, Multiplication, Addition, the Subtraction, this tells you which order to do things in)
As you cant do √10 in the brackets you do the indices, so (√10)³
Split this up to make it easier
(√10)³= √10 x √10 x √10 = 10√10
You the multiply this by 9
9 x 10√10 = 90√10
then multiply by 5
5 x 90√10 = 450√10 = 1423.024947 (using calculator)