Solution - Power equations

Step  1  :

 1.1   

Negative number raised to an odd power is negative

To show this we begin with (-7)⁵ ,a negative number raised to an odd exponent:

(-7)⁵ can be written as (-7)•(-7)•(-7)•(-7)•(-7)

Now, using the rule that says minus times minus is plus, (-7)⁵ can be written as (49)•(49)•(-7) which is a negative number. 

 We showed that (-7)⁵ is a negative number  

 Using the same arguments as above, replacing (-7) by any negative number, and replacing the exponent 5 by any odd exponent, we proved which had to be proved  

  1.2     63 = 3²•7 (-63)¹ = (3²•7)¹ = -3² • 7

Equation at the end of step  1  :

Step  2  :

            ( -32•7)
 Simplify   ————————
               3    

Dividing exponents :

 2.1    3²   divided by   3¹   = 3^{(2 - 1)} = 3¹ = 3

Final result :

  -21