Algebra Examples

$a_{n} = \frac{n (n + 1)}{2}$

Step 1

Substitute in the value of $n$ to find the $n$ th term.

$a_{1} = \frac{(1) ((1) + 1)}{2}$

Step 2

Multiply $1 + 1$ by $1$ .

$a_{1} = \frac{1 + 1}{2}$

Step 3

Add $1$ and $1$ .

$a_{1} = \frac{2}{2}$

Step 4

Divide $2$ by $2$ .

$a_{1} = 1$