a: \(=2\cdot\dfrac{-5}{2}\cdot x^2y^3\cdot x^2y^3=-5x^4y^6\)

Hệ số là -5

Biến là x^4;y^6

Bậc là 10

b: \(=6\cdot\dfrac{1}{3}\cdot x^2y^2z\cdot xy^3=2x^3y^5z\)

Hệ số là 2

Biến là x^3;y^5;z

Bậc là 9

c: =xy^2(8+5-4)

=9xy^2

Bậc là 3

Hệ số là 9

Biến là x;y^2

d: =x^2y(-1/2+1/3-1)

=-7/6x^2y

Hệ số là -7/6

Biến là x^2;y

Bậc là 3

a) 2x(x² - xy³)

= 2x.x² - 2x.xy³

= 2x³ - 2x²y³

b) (12x³y⁵ - 21x⁴y²) : 3x²y²

= 12x³y⁵ : 3x²y² - 21x⁴y² : 3x²y²

= 4xy³ - 7x²

a, 2\(x\).(\(x^2\) - \(xy^3\))

= 2\(x^3\) - 2\(x^2\)y³

b, (12\(x^3\)y⁵ - 21\(x^4\)y²) :(3\(x^2\)y²)

=    3\(x^2\).y².(4\(xy^3\) - 7\(x^2\))

= 4\(xy^3\) - 7\(x^2\)

\(b,=3xy\left(xy+2xy^2-4\right):3xy\\ =xy+2xy^2-4\\ c,=\left[\left(2x^3-x^2+x\right)+\left(6x^2-3x+3\right)\right]:\left(2x^2-x+1\right)\\ =\left[x\left(2x^2-x+1\right)+3\left(2x^2-x+1\right)\right]:\left(2x^2-x+1\right)\\ =\left[\left(x+3\right)\left(2x^2-x+1\right)\right]:\left(2x^2-x+1\right)\\ =x+3\)

b: \(=xy+2xy^2-4\)

a) -5x4y6 

Hệ số là: -5

biến là x⁴y⁶

Bậc là 10

2 x³y⁵z

Hệ số là 2

Biến là x³y⁵x

bậc là 9

-160x³y⁶

Hệ số là : -160

Biến là x³y⁶

Bậc là:9

-1/6x⁶y³

hệ số là -1/6 

Biến là x⁶y³

^{bậc là 9}

a) \(=6x^3+8x^2+2x-6x^3=8x^2+2x\)

b) \(=\left[3xy\left(xy+2xy^2-4\right)\right]:3xy=xy+2xy^2-4\)

c) \(=\dfrac{10x}{\left(x-2\right)\left(x+2\right)}+\dfrac{3}{x+2}-\dfrac{5}{x-2}=\dfrac{10x+3\left(x-2\right)-5\left(x+2\right)}{\left(x-2\right)\left(x+2\right)}=\dfrac{8x-16}{\left(x-2\right)\left(x+2\right)}=\dfrac{8\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}=\dfrac{8}{x+2}\)

a, \(=6x^3+12x^2+2x-6x^3\\=12x^2+2x\)

b,

\(=xy+2xy^2-4\)

c,

\(\dfrac{10x}{x^2-4}+\dfrac{3}{x+2}-\dfrac{5}{x-2}\)

\(=\dfrac{10x}{\left(x-2\right)\left(x+2\right)}+\dfrac{3x-6}{\left(x-2\right)\left(x+2\right)}-\dfrac{5x+10}{\left(x-2\right)\left(x+2\right)}\)

\(=\dfrac{10x+3x-6-5x-10}{\left(x-2\right)\left(x+2\right)}=\dfrac{8x-16}{\left(x-2\right)\left(x+2\right)}=\dfrac{8\left(x-2\right)}{\left(x-2\right)\left(x+2\right)}=\dfrac{8}{x+2}\)

a) \(3xy^3\left(-2x^2yz^3\right)=-6x^3y^4z^3\)

b) \(xy\left(-8xy^4\right)=-8x^2y^5\)

c) \(x^3y\left(-5y^2z\right)=-5x^3y^3z\)

d) \(-x\left(-3x^3y\right)=3x^4y\)

a,  -6x³y⁴z³        ;            b,  -8x²y⁵           ;              c,  -5x³y³z           ;             c,   3x⁴y

(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

\(a,=2xy^3\\ b,=xy+3xy^2-4\\ c,=\left(x-4\right)\left(x+4\right):\left(x-4\right)=x+4\\ d,=\left(x+5\right)^2:\left(x+5\right)=x+5\)

\(a,=\left(x-2\right)^2-y^2=\left(x-y-2\right)\left(x+y-2\right)\\ b,=4x^2\left(x^2+2x+1\right)=4x^2\left(x+1\right)^2\\ c,=xy^2\left(x^2-2xy+y^2\right)=xy^2\left(x-y\right)^2\\ d,=\left(x-y\right)\left(x+y\right)-7\left(x-y\right)=\left(x-y\right)\left(x+y-7\right)\\ e,=\left(5x-2y\right)\left(5x+2y\right)\\ f,=x^2+3x+4x+12=\left(x+3\right)\left(x+4\right)\\ i,=x^2+2x-7x-14=\left(x+2\right)\left(x-7\right)\)