Which term of the AP : 21,18,15,........is -81? Also, is any term 0?
Answers
Answered by
31
-81:
-81=21+(n-1)(-3)
-81-21=(n-1)(-3)
-102/-3=(n-1)
minus minus get cancelled.
so,
n-1=102/3
n-1=34
n=35
so, 35th term is -81
-81=21+(n-1)(-3)
-81-21=(n-1)(-3)
-102/-3=(n-1)
minus minus get cancelled.
so,
n-1=102/3
n-1=34
n=35
so, 35th term is -81
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Answered by
34
Answer:
35
Step-by-step explanation:
a1 = 21 d = a2 - a1
a2 = 18 = 18-21 = -3
an = -81 = a1 + (n-1) d
-81 = 21 + (n-1) (-3)
-81 = 21 - 3n + 3
-81 = 24 - 3n
-81 - 24 = -3n
-105
------- = n
-3
n = 35
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