D   =   ( 9 x 2 y 2   –   6 x 2 y 3 )   :   ( - 3 x y ) 2   +   ( 6 x 2 y   +   2 x 4 )   :   ( 2 x 2 )     ⇔   D   =   9 x 2 y 2   :   ( - 3 x y ) 2   –   6 x 2 y 3   :   ( - 3 x y ) 2   +   6 x 2 y   :   ( 2 x 2 )   +   2 x 4   :   ( 2 x 2 )     ⇔   D   = 1 - 2 3 y + 3 y + x 2 ⇔   D   = x 2 + 7 3 y + 1

Đa thức D = x 2 + 7 3 y + 1  có bậc 2

Đáp án cần chọn là: D

A mới đúng nha bạn

(15³y²-6x²y-3x²y²):6x²y

=\(\dfrac{5}{2}\)xy-1-\(\dfrac{1}{2}\)y

(4x²-9y²):(2x-3y)

=(2x-3y)(2x+3y):(2x-3y)

=2x+3y

\(a,=10x^3-5x^2+5x\\ b,=x^3+27\\ c,=\dfrac{5}{2}xy-1-\dfrac{1}{2}y\\ d,=\left(2x^3-10x^2-11x^2+55x+12x-60\right):\left(x-5\right)\\ =\left[2x^2\left(x-5\right)-11x\left(x-5\right)+12\left(x-5\right)\right]:\left(x-5\right)\\ =2x^2-11x+12\)

a: \(=10x^3-5x^2+5x\)

b: \(=x^3-27\)

Chọn  B

B

B

B

B.2y2+3xy-x2

a) \(\left(6x^2y-\dfrac{1}{2}xy+12y\right)\left(-\dfrac{1}{3}xy\right)=-2x^3y^2+\dfrac{1}{6}x^2y^2-4xy^2\)

b) \(\left(2x+3-y\right)\left(2x-y\right)=4x^2+6x-2xy-2xy-3y+y^2=4x^2+y^2+6x-3y-4xy\)

c) \(3\left(4x+1\right)\left(4x-1\right)-12\left(4x^2+1\right)=3\left(16x^2-1\right)-48x^2-12=48x^2-3-48x^2-12=-15\)

b. (2x + 3 - y)(2x - y)

= 4x² - 2xy + 6x - 3y - 2xy + y²

= 4x² - 4xy + 6x - 3y + y²

= \(\left[\left(2x\right)^2-4xy+y^2\right]\) + (6x - 3y)

= (2x - y)² + 3(2x - y)

= (2x - y + 3)(2x - y)

\(=3y\left(2x^2-y\right)-\left(2x^2-y\right)=\left(3y-1\right)\left(2x^2-y\right)\)

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