Question

Answer 1

Bài 1

a) x² - 4x + 4

= (x - 2)²

b) x² - 6x + 9

= (x - 3)²

c) x² - 10x + 25

= (x - 5)²

Bài 2

a) 4x² - 12x + 9

= (2x - 3)²

b) 25x² - 20x + 4

= (5x - 2)²

c) 1/9 x² - 10/3 x + 25

= (x/3 - 5)²

Answer 2

Bài 3

a) 4x² - 12xy + 9y²

= (2x - 3y)²

b) 9x² - 30xy + 25y²

= (3x - 5y)²

c) 1/4 y² - 1/3 xy + 1/9 x²

= (y/2 - x/3)²

Answer 3

Bài 4

a) y² + 8y + 16

= (y + 4)²

b) y² + 12y + 36

= (y + 6)²

c) y² - 4y + 4

= (y - 2)²

Answer 4

Bài 5

a) 9y² + 6y + 1

= (3y + 1)²

b) 4y² + 28y + 48

= 4(y² + 7y + 12)

= 4(y² + 3y + 4y + 12)

= 4[(y² + 3y) + (4y + 12)]

= 4.[y(y + 3) + 4(y + 3)]

= 4(y + 3)(y + 4)

c) 9y² + 48y + 64

= (3y + 8)²