Question

e="\sf\large\green{\underbrace{\red{Befikra*}}}:" alt="\sf\large\green{\underbrace{\red{Befikra*}}}:" align="absmiddle" class="latex-formula">.
The first term of an arithmetic sequence is 1 and the sum of the first four terms is 100. Find the first four terms​

Answer 1

First term f = 1

If first four terms are f, f + d, f + 2d, f + 3d

f + f + d + f + 2d + f + 3d = 100

4f + 6d = 100 (divided by 2 , both sides )

2f + 3d = 50

2 + 3d = 50

3d = 50 – 2

3d = 48

d = 48/3

d = 16

The arithmetic sequence is 1, 17, 33, 49, ………….