Answer:
r=63
Step-by-step explanation:
Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :
                     r/3-(21)=0             r
 Simplify   —
            3
 r    
  — -  21  = 0 
  3     2.1   Subtracting a whole from a fraction
Rewrite the whole as a fraction using  3  as the denominator :
          21     21 • 3
    21 =  ——  =  ——————
          1        3   
Equivalent fraction : The fraction thus generated looks different but has the same value as the whole
Common denominator : The equivalent fraction and the other fraction involved in the calculation share the same denominator
 
        
             
        
        
        
Divide 754 by 13 and you get 58
Now multiply by 9 and you get 522 miles.
        
                    
             
        
        
        
C3=n
N x 2 - 6 + 2
N < (6x8) - 10
        
             
        
        
        
The lengths of the rectangles are 7 and 12 respectively.  Form the ratio 7/12.  The widths of the rects. are x and 5 respectively.  Form the ratio x/5.  Now equate these two ratios:
7       x
--- = ---
12     5
Solve this for x.  One way to do this would be to cross-multiply, obtaining 12x = 35, and solving this result for x.  x will be a fraction.  Write the numerator and denominator in the boxes given.