Question

Answer 1

giúp mình gấp mn ơi

Answer 2

Answer 3

Bài 1:

5x.(xy - 3y + x)= 5x²y - 15xy + 5x²

Bài 2:

(x + 3).(x² + 3x - 5) = x.(x² + 3x - 5) + 3.(x² + 3x -5)

                                = x³ + 3x² - 5x + 3x² + 9x -15

                                = x³ + 6x² +4x - 15

Bài 3: (5x - 2)² =(5x)² - 2.5x.2 + 2² = 25x² - 20x + 4

Bài 4:

a, = 3x.(x - 2y) - 6y.(x - 2y) = (x - 2y).(3x - 6y)

b, = 3x.(x + 2y) + 6.(x + 2y) = (x + 2y).(3x + 6)