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Exponents and radicals


                  5  3
                a b                                                 7 3
            5.                                        Alternatively,     7 =  33  7 =  0    1 = .    (2)
                                                                           -
                   2
                 ab                                                 7 3
                  k mn   3  4  6  3                 From equations (1) and (2),  it follows that
            6.      2 3 
                  km n
                                                           7  = 1
                                                            0
                  7.      20a b   3    2   ×     5a b  3 25   5  Similarly,  m 4  =  mmmm´ ´ ´  =    1  (3)
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     Mathematics for Secondary Schools  8.    8a b      15a b    Thus,    m 4 4  =  m  m 44    = mmmm´ ´ ´    (4)
                                                                0, then
                                                      if m ¹
                   5ab
                
                                                                     4
                15a b c
                    3 2 2
                                                                            0
                                                                          m
                                                                     -

                                                             m
                    3
                  5a bc
                     4 5
                 48a b
                                                      Therefore, m 0  = 1 by equations (3) and (4).
            9.
                    2 3
                        1
                    3
            10.
                                                       then x  = 1. In this case 0  is not defined.
                                                            0
                                                                              0
                   6r ÷  4r                            Generally, if  x any non-zero number,
                 (3 ´  2  2 ´  15  3 ´  10  25 ) 3
            11                   2                    Negative exponents
                   (3  16  2 ´  16  5 ´  2 )                           8  3
                                                      The expression   8  5  ,   can  be  simplified
                 (3mn ) 3                             using the  division  law of exponents  as
            12.
                  ( 8 mn ) 3                          follows:
                                                           8 3      8 × 8 × 8
                 (3 ´  2  a  3  b ´  4  c ´  2  ) 3        8 5  =  8 × 8 × 8 × 8 × 8
            13.                   2                              1
                 (14 c ´  2  a ´  2  b ´  3  )                 =  8 × 8
                ( 17 ´ ( ) ) 3                                 =    1 2
                           2
                       4x
                    3
            14.                                                 8
                ( ( ) ´  17 2 ) 3                     Therefore,  8  3  =  1  .          (1)
                      2
                  2x
                                                                 8  5  8 2
            15.  (ab+  ) 2                            Also,   8 3  8 =  35 -  8 =  2 -        (2)
                  2
                 a − b 2                                       8 5
           Zero exponent                              Comparing equations (1) and (2), gives
                                                            1
                                                       −
                                                        2
           An expression   7  3 3    can be simplified by   8 =  8 2  . .
                           7
           using the  division  law  of exponents  as             k  5     kkkkk
                                                                             ´´´´
           follows:                                   Similarly,    k  8  =  kkkkkkkk
                                                                        ´´´´´´´

                  7 3  777´ ´
                      =      =    1              (1)                 =   1
                  7 3  777´ ´                                         kkk
                                                                        ´´
                                                                       1
                                                    94               =
                                                                      k 3   Student's Book Form Two


                                                                                          11/10/2024   20:12:17
     MATHEMATIC F2 v5.indd   94
     MATHEMATIC F2 v5.indd   94                                                           11/10/2024   20:12:17
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