# Basic Algebra

### Example 1

Find a pattern then fill in the next two numbers: 0, 1, 5, 14, 30, ____, ____

### Example 2

A triangle has no diagonals, while a quadrilateral has 2, a pentagon has 5, and a hexagon has 9. Without drawing the figure, how many diagonals will a septagon (7-sided figure) have?

### Example 3

The numbers 1–9 are arranged in a certain order. Find the missing numbers.

8 5 4 ___ 1 7 6 ___ ___