A graphing calculator is a great help for problems of this nature.
  x ∈ {-5.63, -0.55, 2.59}
 
        
        
        
Answer:
Perimeter of a square=circumference of circle
4×22=2πr
44=πr
r=14
Area of circle=πr2
22/7×14×14
28×22
616
 
        
                    
             
        
        
        
Answer:
-1 1/3
Step-by-step explanation:
 
        
                    
             
        
        
        
d = r · t ⇒ t = d/r
going
t = 54/(r + 4)
coming
t = 30/(r - 4)
54/(r + 4) = 30/(r - 4) times are equal
54(r - 4) = 30(r + 4) product means/extremes
54r - 216 = 30r + 120 distribute
24r - 216 = 120 subtract 30r from both sides
24r = 336 add 216 to both sides
r = 14 divide both sides by 24
Alfonso bikes at 24 mph.