Question

find the arithmetic sequence whose 34th term is -39 and whose 50th term is -71?​

Answer 1

Answer:

Given:-

34th term = -39

50th term = -71

a+33d = -39 _______eq.1

a+49d = -71 ________eq.2

(balancing equation 1 and 2)

multipy eq.2 with -1

a+33d = -39

(a+49d = -71) ×-1

-a-49d = 71

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a-a+33d-49d = -39+71

-16d = 32

d=32/-16

d= -2

putting the value of d in equation 1.

a+33d = -39

a+33×-2 = -39

a-66 = -39

a=-39+66

a=27

Now, a=27 and d= -2

Thus,arithmetic sequence:-

a+d=27+(-2)=25

a+2d=27+(2×-2)=23

a+3d=27+(3×-2)=21

a+4d=27+(4×-2)=19

:-25,23,21,19,...