226 Answer Key

9. 
   

4424

218

2

2

xy xy y

x

4 xy−

=

4

2

y()x^2 x 6

()x^29

=

22

2

⋅ (^2) ()+ (^2) () 3
()^3 ()−^3
y(
(^3) )(

2 2
2
()()xx^33322 yy()x^2
()()xx^333 ()x+^3

2
3
y
x
()x^2

• 
  

10. xy
    xy^33 y

=

()xy⋅

()xy()xxxyyy

1

++xy y

= 221

xx^2 xyyy

11. 
    

xx

x

x

x

2

2

44

9

26 x

2

4 xx

−

⋅

−

=

()()

()+ ()

⋅

()

()−

− )(

+ )(

))(( −

))(( −

2 ( −

=

()()()

()+ ()()

⋅

()()

()()−−

−− )(

+ )(

))(( −

))(( −−

(^2) ( −−

()

• (^2) ( −
  x 3

12. 
    

    x
    x
    x
    x
    −
    ÷
    1 +
    21 x−
    1
    42 x−

    
    

    −
    ⋅

    
    

• 
  

  x
  x
  x
  x
  1
  21 x−
  42 x−
  1
  = ()
  −
  ()
  ⋅ ()
  −
  − ()+
  (^2) (

  
  

  ()−
  ()()
  ⋅
  ()()−
  −− ()+
  (^2) (
  = ()

  
  


• 
  

  (^2) ( −
  x 1

  
  

13.^2
23

4

xx^2222 x^3

+

−

=

()+ ()

+

()−

2

)( −

4

+ ))((

=

()+ ()

+

()

()+ ()

2

)( −

4 ( +

+ ))(( + )))((( −

=

()+ ()

+

()+ ()

2

)( −

44 +

+ ))(( )( −

x

+ ))((

=

()+ ()

46 +

)( −

x

+ ))((

=

()+

()+ ()−

22 3

13

x

xx