the 17th term of an A.P is 5 more than twice its 8th term. if the 11th term of the A.P is 43 find the nth term

Given

17th term =2( 8th term) + 5

a+(17-1)d = 2(a+(8-1)d )+5

a+16d =2a+14d+5

-a+2d=5 ...(1)

Also given

11th term = 43

a+(11-1) d=43

a+ 10d =43 ...(2)

(1)+(2), 12d = 48==>d=4

(1)==? -a+8 = 5

-a = -3

a=3

So, a=3 and d=4;

nth term = a+(n-1)d = 3+(n-1)4 = 3+4n-4=4n-1

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