X 2 5x 1 4 0
- X 4 5x 3 8x 2 5x 1 0
- X 4 5x 3 6x 2 5x 1 0
- X 5 5x 4 10x 3 10x 2 5x 1 0
- 2 x 5 0 5x 1 2x 4 0 25
- X 4 5x 3 12x 2 5x 1 0
- X 4 5x 3 2x 2 5x 1 0
- X 4 5x 3 4x 2 5x 1 0
- X 1 2 5x 1 4 6 0
- By first completing the square solve x 2 5x 1 4 0
- 2 5x 1 4 5 8x 0 25 x
- X 5 5x 4 9x 3 9x 2 5x 1 0
- 2x 4 5x 2 x 1 0
- 3x 2 5x 1 )( x 2 4 )= 0