Question

3.What should be added to twice the rational number -7/3 to get 3/7 ?

-107/21

107/21

21/107

-21/107

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Answer 1

Answer:

-81/21

Step-by-step explanation:

Let the unknown no. be 'x'

What should be added to 'twice' the no., to get 3/7

      2 × (-7)                3

∴   -----------  +  x  =  ------

          3                      7

-14              3

------- + x = ------

  3               7

14 + 3x         3

----------  =  -------

    3              7

Cross multiplying, we get:

7(14 + 3x) = 3×3

 98 + 21x = 9

          21x = 9 - 98

          21x = -89

                    -89

          ⇒ x = ------

                      21

Hence, -89/21 should be added to twice -7/3 to get 3/7