Answer: x^4X\sqrt{x}
Step-by-step explanation: x9" was replaced by "x^9". 
Rules for simplifing variables which may be raised to a power: 
 
 (1) variables with no exponent stay inside the radical 
 (2) variables raised to power 1 or (-1) stay inside the radical 
 (3) variables raised to an even exponent: Half the exponent taken out, nothing remains inside the radical. examples: 
 (3.1) sqrt(x8)=x4 
 (3.2) sqrt(x-6)=x-3 
 
 (4) variables raised to an odd exponent which is >2 or <(-2) , examples: 
 (4.1) sqrt(x5)=x2•sqrt(x) 
 (4.2) sqrt(x-7)=x-3•sqrt(x-1) 
 
 Applying these rules to our case we find out that 
 
 SQRT(x9) = x4 • SQRT(x) 
 
Simplified Root : 
 x4 • sqrt(x)