\(a,\Rightarrow x\left(x+3\right)-\left(x-3\right)\left(x+3\right)=0\\ \Rightarrow\left(x+3\right)\left(x-x+3\right)=0\\ \Rightarrow3\left(x+3\right)=0\Rightarrow x=-3\\ b,A:B=\left(2x^2-x+4x-2\right):\left(2x-1\right)\\ =\left[x\left(2x-1\right)+2\left(2x-1\right)\right]:\left(2x-1\right)\\ =x+2\)

\(a,=\dfrac{5x+30+x^2-30}{x\left(x+6\right)}=\dfrac{x\left(x+5\right)}{x\left(x+6\right)}=\dfrac{x+5}{x+6}\\ b,=\dfrac{3x^2+4x+1-x^2+2x-1-x^2-2x+3}{\left(x-1\right)^2\left(x+1\right)}\\ =\dfrac{x^2+4x+3}{\left(x-1\right)^2\left(x+1\right)}=\dfrac{\left(x+1\right)\left(x+3\right)}{\left(x-1\right)^2\left(x+1\right)}=\dfrac{x+3}{\left(x-1\right)^2}\)

\(c,=\dfrac{3x^2+2x+1+x^2-2x+1-2x^2-2x-2}{\left(x-1\right)\left(x^2+x+1\right)}\\ =\dfrac{2x^2-2x}{\left(x-1\right)\left(x^2+x+1\right)}=\dfrac{2x\left(x-1\right)}{\left(x-1\right)\left(x^2+x+1\right)}=\dfrac{2x}{x^2+x+1}\)

`a, (5ab - 2a^2):a`

`= 5b - 2a`

`b, (6x^2y^2-xy^2+3x^2y) : (-3xy)`

`= -2xy + y/3 - x`.

a) (-x⁶ + 5x⁴ – 2x³) : (0,5x²)

= (-x⁶ : 0,5x²) + (5x⁴ : 0,5x²) + (-2x³ : 0,5x²)

= -2x⁴ + 10x² – 4x

b)

`a, 20x^3y^5 : 5x^2y^2`

`= (20:5)x^(3-2) . y^(5-2)`

`= 4xy^3`

`b, 18x^3y^5 : (3(-x^3)y^2)`

`= -(18:3)y^(5-3)`

`= -6y^2`

Thực hiện phép chia:

a) (-y^2):y^4=\(\dfrac{-1}{y^2}\)

b) (-x)^5:(-x)^3=(-x)^2

a) (-y²) : y⁴=

a) \(\left(-y^2\right):y^4=\dfrac{-1}{y^2}\)

b) \(\left(-x\right)^5:\left(-x\right)^3=\left(-x\right)^2=x^2\)

`a, (4x^3y^2 - 8x^2y + 10xy) : 2xy`

`= 2x^2y - 4x + 5`.

`b, 7x^4y^2 - 2x^2y^2 - 5x^3y^4 : 3x^2y`

`= 7/3 x^2y - 3/2y - 5/3xy^3`

a: =x^4-3x^5+4x^8

b: =2x^3+2x^2+4x

c: =4x^2+8x-5

d: =2x+3x^2+7x^4

a: \(\dfrac{20a^4b^5c^2}{\left(-5ab^2c\right)^2}\)

\(=\dfrac{20a^4b^5c^2}{25a^2b^4c^2}\)

\(=\dfrac{4}{5}a^2b\)

b: \(\dfrac{\left(-15x^2y^3\right)^7}{\left(15xy^3\right)^6}-\dfrac{32x^{18}y^5}{\left(-4x^5y\right)^2}\)

\(=\dfrac{-15^7\cdot x^{14}\cdot y^{21}}{15^6\cdot x^6\cdot y^{18}}-\dfrac{32x^{18}y^5}{16x^{10}y^2}\)

\(=-15x^8y^3-2x^8y^3\)

c: \(\dfrac{-\dfrac{1}{3}x^5y^2}{-2xy}-\dfrac{x^2+2x+1}{x+1}\)

\(=\dfrac{2}{3}x^3y-x-1\)