Arithmetic
Example 2

Write the first four terms of a sequence given that the nth term is an = 2n + 3.

Step 1. Find the first term. To find the first term, a1, substitute n = 1 into the formula and solve.

a1 = 2(1) + 3

a1 = 5

Step 2. Find the second term. To find the second term, a2, substitute n = 2 into the formula and solve.

a2 = 2(2) + 3

a2 = 7

Step3. Find the third term.

a3 = 2(3) + 3

a3 = 9

Step 4. Find the fourth term.

a4 = 2(4) + 3

a4 = 11

The first four terms of the sequence are 5, 7, 9, and 11.