3 √ [27x - 81] - 5 =
3 √ [ 27 (x - 3) ] - 5 [Note 3√27 = 3 ]
3 3√ (x - 3) - 5
This is the cube root function vertically stretched by a factor of 3
Shifted to the right 3 units
And shifted down 5 units
Here's the graph of both :
https://www.desmos.com/calculator/man8dgxb7u