Question

write the first three terms of each of the arithmetic sequences described below: 1) first term 30; the sum of the first three terms is 300. 2) first term 30; the sum of the first four terms is 300. 3) first term 30; the sum of the first five terms is.4) first term 30; the sum of the first six terms?​

Answer 1

Answer:

Let three terms be a+d, a and a-d

Sn=300,i.e 300 3=a=100

a-d=30i.e,d=70

Now Sn=6/2(2*30+5*70)

=1230

Answer 2

Answer:

(1) 30, 100, 170

(2) 30, 60, 90

refer to the attachment