PLEASE HELP WILL MARK BRAINLIEST 
                                             
                                          
                                          
                                        
											 
											Answer:
10
Step-by-step explanation:
√81 = 9 (9+9-4*2)
4 * 2 = 8 (9+9-8)
9 + 9 = 18 (18 - 8)
18 - 8 = 10