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(Barré) #1

= ( 3 1 )( 9 3 1 )
27


(^12)
a a  a
Here, in the second solution, the factors involving the variables are with integral
coefficients. This result can be expressed as the first solution :
( 3 1 )( 9 3 1 )
27
(^12)
a a a
= ( 9 3 1 )
9
1
( 3 1 )
3
(^12)
a u a  a
= ̧
¹
·
̈
©
§  
̧
¹
·
̈
©
§ 
9
1
3 3
1 2 a
a a
Example 13. Resolve into factors : x^3  6 x^2 y 11 xy^2  6 y^3.
Solution : x^3  6 x^2 y 11 xy^2  6 y^3
= {x^3  3 ˜x^2 ˜ 2 y 3 ˜x( 2 y)^2 ( 2 y)^3 }xy^2  2 y^3
= (x 2 y)^3 y^2 (x 2 y)
= (x 2 y){(x 2 y)^2 y^2 }
= (x 2 y)(x 2 yy)(x 2 yy)
= (x 2 y)(x 3 y)(xy)
= (xy)(x 2 y)(x 3 y)
Activity : Resolve into factors:




  1. 3
    1
    6
    7
    2
    (^12)
    x  x 2.
    8
    3 1
    a 3. 16 x^2  25 y^2  8 xz 10 yz
    Exercise 3⋅ 3
    Resolve into factors (1 to 43) :




  2. a^2 abacbc 2. abab 1




  3. (xy)(xy)(xy)(yz)(xy)(zx) 4. ab(xy)bc(xy)




  4. 9 x^2  24 x 16 6. a^4  27 a^2  1




  5. x^4  6 x^2 y^2 y^4 8. (a^2 b^2 )(x^2 y^2 ) 4 abxy




  6. 4 a^2  12 ab 9 b^2  4 c^2 10. 9 x^4  45 a^2 x^2  36 a^4




  7. a^2  6 a 8 y^2  2 y 12. 16 x^2  25 y^2  8 xz 10 yz




  8. 2 b^2 c^2  2 c^2 a^2  2 a^2 b^2 a^4 b^4 c^4 14. x^2  13 x 36




  9. x^4 x^2  20 16. a^2  30 a 216



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