SOLUTION: x,2x+1,11 are three consecutive terms of an arithmetic sequence. Calculate(i) x.(ii) the 30th term.
Algebra ->
Sequences-and-series
-> SOLUTION: x,2x+1,11 are three consecutive terms of an arithmetic sequence. Calculate(i) x.(ii) the 30th term.
Log On
You can put this solution on YOUR website! x,2x+1,11 are three consecutive terms of an arithmetic sequence. Calculate(i) x.(ii) the 30th term.
———————————
x,2x+1,11 are the first three terms of an arithmetic sequence. Calculate(i) x.(ii) the 30th term.
———————————
x + d = 2x + 1 —> d = x + 1 (1)
(2x + 1) + d = 11 —> d = 10 - 2x (2)
Set (1) equal to (2): x + 1 = 10 - 2x
3x = 9
x = 3
d = x + 1 —> d = 4
(i)
(ii) To find an answer, it must be assumed that the three terms given are the FIRST three terms (or at least their position m must be given) of the sequence (the problem statement does not provide sufficient information).
...
