Question

The first term of an arithmetic sequence is 10 and the sum of the first four terms is 400. Find the first four terms​

Answer 1

Answer:

hope it help you bro okay

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Answer 2

Answer:

Given,

a = 10

Sn = S4 = 400

a1, a2, a3, a4 = ?

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

S4 = 4/2 [2×10+(4-1)d]

400/2 = 20+3d

200-20 =3d

180 =3d

d= 60

a1 = 10

a2 = a+d = 10+60 = 70

a3 = a+2d = 10+2×60 = 130

a4 = a+3d = 10+3×60 = 190

first four terms of Ap are : 10, 70, 130, 190