1) x² + 10x + 26 = ( x² + 10x + 25) + 1 = (x + 5)² + 1
2) x² - 18x +80 = (x² - 18x + 81) - 1 = (x - 9)² - 1
3) 4x² - 12x + 17 = (4x² - 12x + 9) + 8 = (2x - 3)² + 8
1) x² + 10x + 26 =
= x² + 10x + 25 + 1 =
= (x² + 2•5•x + 5²) + 1 =
= (x + 5)² + 1
2) x² - 18x + 80 =
= x² - 18x + 81 -1 =
= (x² - 2•9•x + 9²) - 1 =
= (x - 9)² - 1
3) 4x² - 12x + 17 =
= 4x² - 12x + 9 + 8 =
= ((2x)² - 2•2x•3 + 3²) + 8 =
= (2x - 3)² + 8
