Question

Thu gon :

a, 2x * (x-1)-3x * (x+1)

b, (x-1) * (x+2) - (x-2) * (x+1)

c, (x-1)^2 - (x+2)^2

d, (2x-1) * (2x-1) -4 ( x+1)^2

Answer 1

a, 2x(x-1) - 3x(x+1)

= 2x² - 2x - 3x² - 3x

= -x² - 5x

b, (x-1)(x+2) - (x-2)(x+1)

= x² + 2x - x - 2 - x² - x + 2x + 2

= 2x

c, (x-1)² - (x+2)²

= x² - 2x + 1 - x² - 4x + 4

= -6x + 5

d, (2x-1)(2x-1) - 4(x+1)²

= 4x² - 2x - 2x + 1 - 4(x² + 2x + 1)

= 4x² - 2x - 2x + 1 - 4x² - 8x - 4

= -12x - 3

Chúc bạn học tốt!

Answer 2

a) 2x . (x-1) - 3x . (x+1)

= 2x² - 2x - 3x² - 3x

= - x² - 5x

= - x (x +5)

b) (x - 1) . (x + 2) - (x - 2) . (x + 1)

= x² + 2x - x - 2 - x² + x - 2x - 2

= - 4

c) (x - 1)² - (x + 2)²

= (x - 1 -x -2) (x + 1 + x + 2)

= - 3 (2x + 3)

d) (2x - 1) . (2x - 1) - 4 (x + 1)²

=