Question

If nth term of a sequence is given by the formula an = 10- 3n find the sum of 20 terms

Answer 1

Answer:

refer to the attachment

Answer 2

Answer:

990 is the answer

see the

Step-by-step explanation:

Tn=5n-3

T1=5(1)-3=2

T2=5(2)-3=7

d=T2-T1

=7-2=5

a=T1=2

S20=20/2(2a+19d)

10(4+95)

990

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