which term of the A.P. 21,42,63,84,_ _ _ is 231?
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Answered by
11
a = 21
d = 21
an = 231
=> an = a + (n-1) d
=> 231 = 21 + (n-1) 21
=> 231 - 21 = (n - 1) 21
=> 210/21 = n - 1
=> 10 = n -1
=> n = 11.
d = 21
an = 231
=> an = a + (n-1) d
=> 231 = 21 + (n-1) 21
=> 231 - 21 = (n - 1) 21
=> 210/21 = n - 1
=> 10 = n -1
=> n = 11.
jasmin6695:
good...
Answered by
1
Answer:11
Step-by-step explanation:
An=a+(n-1)d
Using this formula
231=21+(n-1)21
231-21=(n-1)21
210/21=(n-1)
10=(n-1)
n=11
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