10th CBSE math solution for exercise 5.2 part 3

This page 10th CBSE math solution for exercise 5.2 part 3 is going to provide you solution for every problems that you find in the exercise no 5.2 part 1

10th CBSE math solution for exercise 5.2 part 3

(iii) 5, ____ , _____ , 9 ½

Solution:

a = 5     a₄ = 9 ½

              = (18 - 1)/2

              = 17/2

            a + 3 d = 17/2

            5 + 3 d = 17/2

                  3 d = (17/2) - 5

                   3 d = (17 - 10)/2

                    3 d = 7/2

                        d = 7/(2 x 3)

                         d = 7/6

a= a + d

    = 5 + (7/6)

    = (30 + 7)/6

    = 37/6

a = a + 2 d

     = 5 + 2(7/6)

     = 5 + (7/3)

     = (15 + 7)/3

     = 22/3


(iv) -4,____,____,___,_____,6

Solution:

a = -4

a= 6

a + 5 d = 6

-4 + 5 d = 6

         5 d = 6 + 4

          5 d = 10

              d = 10/5

               d = 2

Second term = a₂ = a + d 

                            = -4+2

                        a₂ = -2

Third term a= a + 2 d 

                     = -4+2 (2)

                     = -4 + 4

               a₃ = 0

Fourth term = a + 3 d

                     = -4+3 (2)

                     = -4 + 6

               a ₄  = 2

Fifth term = a + 4 d

                 = -2 + 4 (2)

                 = -2 + 8

                 = 6    


(v) ______,38 , ______ , ______ , ____ , -22

Solution:

a ₂ = 38

a₆ = -22

a + d = 38 --------(1)

a + 5 d = -22 --------(2)

(2) - (1)

       a + 5 d = -22

     a +  d = 38

     (-)   (-)  (-)

    --------------

          4 d = -60

              d = -60/4

              d = -15

 Substitute d = -15 in the first equation 

  a + d = 38

  a - 15 = 38

      a = 38 + 15

       a = 53

First term = 53

a ₃ = a + 2d = 53 + 2 (-15) = 23

a ₄ = a + 3d = 53 + 3 (-15) = 8

a ₅ = a + 4d = 53 + 4 (-15) = -7

Therefore first,third,fourth and fifth terms are 53,23,8 and -7 respectively.





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