Question

Answer 1

Bài 5

a) x² + 10x + 26 + y² + 2y

= (x² + 10x + 25) + (y² + 2y + 1)

= (x + 5)² + (y + 1)²

b) a² - 6a + 5  - b² - 4b

= (a² - 6a + 9) - (b² + 4b + 4)

= (a - 3)² - (b + 2)²

c) x² - 2xy+ 2y² + 2y + 1

= (x² - 2xy + y²) + (y² + 2y + 1)

= (x - y)² + (y + 1)²

d) 4x² - 12x - y² + 2y + 8

= (4x² - 12x + 9) - (y² - 2y + 1)

= (2x - 3)² - (y - 1)²