She is wrong she should have added 18 to both sides
        
             
        
        
        
Answer:
9
Step-by-step explanation:
2/3 x 2 is 1, 1/3 another will make 2 aprons do that 3 more times and u will run out of fabric and will have 9 aprons
 
        
                    
             
        
        
        
Equate whats inside (arguments)  with base period of sine function
 with base period of sine function  and solve for x to get period,
 and solve for x to get period,

So the period of the graph of the given function is precisely 2.
Hope this helps :)
 
        
             
        
        
        
F(x)=2x+3. easy as that, just replace y with f(x)
        
                    
             
        
        
        
X^2-6x=13
(x-3)^2-9=13
(x-3)^2=22
(x-3)= +-sqrt22
x = sqrt22+3 or x = -sqrt22+3