Example 1

x² − 5x + 6 = 0 → roots: 2 and 3

Example 2

2x² + 3x − 2 = 0 → roots: 0.5 and −2

Example 3

x² − 4 = 0 → roots: ±2

Example 4

x² + 4x + 4 = 0 → double root: −2

Example 5

x² + 1 = 0 → complex roots: ±i