2x+1,4x-1,5x+1 are in the arithmatic sequence . find the value of x .write its nth term .find the position of 195
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In an AP,
→ a₂ - a₁ = a₃ - a₂ = d
⇒4x - 1 - (2x + 1) = 5x + 1 - (4x - 1)
⇒4x - 1 - 2x - 1 = 5x + 1 - 4x + 1
⇒2x - 2 = x + 2
⇒2x - x = 2 + 2
⇒x = 4
By substituting the value of x in a₁ :-
2x + 1 = 2(4) + 1
⇒a₁ = 9
Common difference, d = a₂ - a₁
⇒d = 4(4) - 1 - a₁
⇒d = 15 - 9
⇒d = 6
Now,Let 195 be the nth term of the AP.
We know,
aₙ = a + (n - 1)d
Substituting the values :-
195 = 9 + (n - 1)6
→195 - 9 = 6n - 6
→186 + 6 = 6n
→192 = 6n
→n = 192/6
→n = 32
Therefore, 195 is the 32nd term of the AP.
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