if a2 is 2 and a7 is 22 tell me what is the sum of first 35 number
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Answer:
a2
a+d=2
a=2-d.......(1)
a7
a+6d=22
2-d+6d=22 (from 1)
2+5d=22
5d=20
d=4
putting value of d in equation 1,
a=2-d
a=2-4
a=-2
now n=35,a=-2 and d=4
Sn = n/2(2a+(n-1)d
= 35/2[2*(-2) +(35-1)]*4
=35/2[-4+34*4]
=35/2[-4+136]
=35/2*132
=35*66
=2310
Step-by-step explanation:
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