SOLUTION: For a given arithmetic sequence, the 42nth term, a42, is equal to 194, and the 88th term, a88, is equal to 424.
Find the value of the 10th term, a10.
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-> SOLUTION: For a given arithmetic sequence, the 42nth term, a42, is equal to 194, and the 88th term, a88, is equal to 424.
Find the value of the 10th term, a10.
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Question 1144719: For a given arithmetic sequence, the 42nth term, a42, is equal to 194, and the 88th term, a88, is equal to 424.
Find the value of the 10th term, a10.
= a + 41*d = 194. (1)
= a + 87*d = 424. (2)
The unknown "a" is the first term, and the unknown "d" is the common difference of the AP.
Thus you have the system of 2 linear equations in 2 unknown, so it is solvable.
The easiest way to solve it is to subtract equation (1) from equation (2). You will get
87d - 41d = 424 - 194
46d = 230
d = 230/46 = 5.
Then from equation (1), a = 194 - 5*41 = -11.
Now you know EVERYTHING about your AP. In particular,
= a + 5*9 = -11 + 45 = 34. ANSWER