Question

a is 1 d is 2 then find s10

Answer 1

LOOK AT ATTACHMENT,✎✍✍

Answer 2

$\huge\mathcal{Heya}$

Given :-

First term, a = 1

Common Difference, d = 2

To find :-

${S_1_0}$ = ?

Solution :-

First we find ${a_1_0}$

Using formula,

${a_n}$ = a + (n - 1)d

So,

${a_1_0}$ = 1 + (10 - 1)2

${a_1_0}$ = 1 + 9 × 2

${a_1_0}$ = 1 + 18

${a_1_0}$ = 19

Now,

${S_1_0}$ = n / 2 (a + ${a_1_0}$)

Putting values

${S_1_0}$ = 10 / 2 (1 + 19)

${S_1_0}$ = 5 × 20

${S_1_0}$ = 100

$\huge\mathbb{Hope \ this \ helps.}$