Question

plz plz help me!!!


I need step by step explanation ​

Answer 1

Answer:

n=7,S7=805 and d=23

by using formula we will get,

S7=n/2[2a+(n-1)d]

805=7/2[2a+(7-1)23]

805=7/2[2a+(6)23]

805×2=7(2a+138)

1610=7(2a+138)

1610/7=2a+138

1610/7-138=2a

(1610-966)/7=2a

644/7=2a

92=2a

a=92/2

a=46

so, the answer is 46.

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