Page 111 - Mathematics_Form_Two
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Exponents and radicals


              they  process two batches  of plastic   Solution
               waste.  The  first  batch  can  be     (a)    3×  5 =   15
               processed at a rate of   3  81  tons per
               day, while  the second batch can be    (b)   Given that  2× 32, it follows,

               processed at a rate of   2 24  tons           32 =  22222´´´´
                                        3
               per  day.  What  is the  total  amount
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               of plastic waste processed per day               =  42
               when the two batches are combined?      Thus, 2´ 32´ 2´ 32 32 =2 4 2= 2 4 2=  ´ ´ 2 4 2´
                                                             2
               Simplify your answer.                                 = 14        2 ´ 2  2
                                                                        =
                                                                     =
                                                                        = 14´´ 2´´
                                                                         14´´ 2 ´ 2´
           4. A hospital is studying two new                         = 14´´
                                                                        = 14´´
                                                                     =
                                                                         14 2´´ 2 2
              medications,  each  with  a  different                    =  8                         Mathematics for Secondary Schools
                                                                        = 8 8
              absorption rate  in the body.  The                     = =   = 8
              absorption rate for the first medication
              is  80 mg/hour, and for the second       (c)  Given  20× 28, it follows that,
                 4
                                    4
              medication,  it is  35  mg/hour.               20 =   2 2 5 2´´ =     5
              What  is  the  difference  in  absorption
              rates  between the  two medications?           28 =  2 2 7 2´´ =      7
              Simplify your answer.
                                                              Thus, 20´   28 2 5 2 7
                                                                             =
                                                                                   ´
                                                                 Thus, 20´
                                                                                        ´
                                                                               28 2 5 2 7
                                                                                  =
                                                                                       7
                                                                          22
                                                                               22
                                                                             = ´´
           Multiplication of radicals                                    = ´´     5´  5´   7
                                                                                ´
           Multiplication  of  radicals involves                         =  4´  =  57 57
                                                                               4´
                                                                                     ´
           multiplying  the  numbers inside  the
                                                                             =
           radicals and then simplifying if possible.                    =  4 35 4 35
           Thus, when multiplying  radicals, the
           indices must be the same. Otherwise, it is   (d)   1  2  (  3  5 +  )  4=  3 ´  (  3  5 +  )
           impossible.
            Generally,   n  a ´  n  b =  n  ab                            = 2 3 (  3+ 5  )

           Example 5�32                                                   23=  ´  3 +  23 ´    5
           Simplify each of the following                                      = 2 3 2 15= ´ + 3 2 15= 2´ +
           expression products:

            (a)   3        5´  (b)    2´   32                                  =  6 2 15+

                                                       (e)  Given  2 3 − (  2 ×  ) (  3 3 2+  )
            (c)   20´   28     (d)    12 ( 3 +  5 )

                                                           Expand as follows;
            (e) ( 2 3− 2 ×      3+3 2   )                  ( 23 -   2 ´  ) (  3 32 =  23´     3 +  23 32 + - ) (    2 ´  3 + - ) (  2 32 )
                           ) (
                                                                                  ) (
                                                                                               ) (
                                                                                                                                  ´
                                                                                                       ´
                                                                            +
                                                                                                     -
                                                                                    =  29 6 6 -     6 34
                                                                                          +
                                                                                      23 5 6 32
                                                   105                              = ´ +       -´
           Student's Book Form Two
                                                                                      6 56 6
                                                                                    =+       -
                                                                                      665 6
                                                                                    = - +
     MATHEMATIC F2 v5.indd   105
                                                                                          11/10/2024   20:12:30
     MATHEMATIC F2 v5.indd   105                                                          11/10/2024   20:12:30
                                                                                    = 56
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