How to find the sum first 16
multiples of 7? I
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Answer:
- 7 ,14,21,..140 are first 20 terms
- these are in AP
- first term =a = 7
- n= 20
- d= a2-a1 = 14-7=7
- last term = l=140
- sum of n terms Sn = n/2 [a+last term]
- s20 = 20/2[7+140]
- =10*147
- =1470
Step-by-step explanation:
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