SOLUTION: If the 4
th term of a AP is 16 and the 8
th term is 28
Find:- a) the first term
b) the common difference
c) The 16th term
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-> SOLUTION: If the 4
th term of a AP is 16 and the 8
th term is 28
Find:- a) the first term
b) the common difference
c) The 16th term
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Question 1109076: If the 4
th term of a AP is 16 and the 8
th term is 28
Find:- a) the first term
b) the common difference
c) The 16th term Answer by ikleyn(52778) (Show Source):
the 4-th term is = = 16 (1)
the 8-th term is = = 28. (2)
Subtract eq(1) from eq(2). You will get
7d - 3d = 28 - 16 = 12 ====> 4d = 12 ====> d = = 3.
Thus you just found the common difference d. It is 3.
Next, from eq(1) = 16 - 3d = 16 - 3*3 = 7.
Thus, the first term = 7.
Then the 16-term is = = 7 + 15*3 = 52.
