Solution - Power equations

Step  1  :

 1.1     10 = 2•5

(10)² = (2•5)² = 2² • 5²

Equation at the end of step  1  :

  (117)    
  ————— -  (22•52)
  (115)    

Step  2  :

Equation at the end of step  2  :

  (117)    
  ————— -  (22•52)
   115     

Step  3  :

Equation at the end of step  3  :

  117    
  ——— -  (22•52)
  115    

Step  4  :

            117
 Simplify   ———
            115

Dividing exponents :

 4.1    11⁷   divided by   11⁵   = 11^{(7 - 5)} = 11²

Equation at the end of step  4  :

  121 -  (22•52)

Step  5  :

Final result :

  21