Find the sum of the ap
5 + 12 + 19 + 26 ------- 145
Answers
Answered by
1
Answer:
a=5
d=12-5 = 7
añ= 145
n=?
an= a+(n-1)d
145= 5+(n-1)7
145-5 = (n-)7
140 =(n-1)7
(n-1) = 140÷7
(n-1) =20
n-1=20
n=20+1
n=21
Answered by
0
Answer:
21
Step-by-step explanation:
145=5(n-1) (7)
145-5=7(n-1)
140=7(n-1)
20=n-1
n=21
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