The Chemistry Maths Book, Second Edition

(Grace) #1

1.9 Exercises 29


1.9 Exercises


Section 1.2


Calculate and express each result in its simplest form:




  1. 31 + 1 (−4) 2. 31 − 1 (−4) 3.(−3) − 1 (−4) 4.(−3) 1 × 1 (−4) 5. 31 × 1 (−4)




  2. 81 ÷ 1 (−4) 7.(−8) 1 ÷ 1 (−4) 8. 9. 10.










































Section 1.3


Factorize in prime numbers:



  1. 6 23. 80 24. 256 25. 810


Simplify by factorization and cancellation:


















Find the value of:


30.2! 32.7! 33.10!


Evaluate by cancellation:


















Section 1.4


Express as decimal fractions:



  1. 10


− 2


  1. 21 × 110


− 3


  1. 21 + 131 × 110


− 4

1 + 151 × 110


− 6













Find the repeating sequence of digits in the nonterminating decimal fraction representation of:


















Use the rules of rounding to give each of the following to 8, 7, 6, 5, 4, 3, 2 and 1 significant figures:



  1. 12131 = 1 0.07692 3076923 48. 49.π 1 = 1 3.141592 653589


Section 1.6


Simplify if possible:


50.a


2

a


3

51.a


3

a


− 3

52.a


3

a


− 4

53.a


3

2 a


2

54.a


5

2 a


− 4

55.(a


3

)


4

56.(a


2

)


− 3

57.(1 2 a


2

)


− 4

58.a


122

a


123

59.(a


2

)


322

60.(a


3

b


6

)


223

61.(a


3

1 + 1 b


3

)


123


  1. 9


122


  1. 8


223


  1. 32


325


  1. 27


− 423

Evaluate:



  1. 71 − 131 × 12 67. 71 − 1 (3 1 × 1 2) 68.(7 1 − 1 3) 1 × 12 69. 71 + 131 × 141 − 15


70.(7 1 + 1 3) 1 × 141 − 15 71. 41 ÷ 121 × 171 − 12 72. 41 ÷ 121 + 171 × 12 73. 81 × 121 ÷ 141 ÷ 12



  1. 31 + 14


2


  1. 31 + 141 × 15


2


  1. 251 + 1144


122

77.(5


2

1 + 112


2

)


122

2 1 414213562373=.


1


17


1


21


1


11


1


9


5


32


1


25


3


8


10


73


!


!!


5


32


!


!!


6


3


!


!


3


2


!


!


768


5120


63


294


21


49


3


18


1


3


1


9


÷


2


15


4


5


÷


2


3


5


3


÷


3


4


4


5


÷









×−








2


3


3


4


2


3


5


6


×


2


3


4


×


1


2


3


4


×


11


12


3


16






1


18


2


27



1


14


2


21






2


9


5


6



3


4


5


7



1


4


1


8





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