Đề bàiyêu cầu gì?

a. \(25xy^2.-\dfrac{1}{5}xy^3=-5x^2y^5\) -Bậc: 7

b.\(-5x^2y^2.3xy^2z=-15x^3y^4z\)  - Bậc: 8

c.\(12xy^2.4xyz=48x^2y^3z\) - Bậc: 6

d. \(-5x^2yz^2.2x^2z=-10x^4yz^3\) ; Bậc: 8

a, \(=-5x^2y^5\)bậc 8 

b, \(=-15x^3y^4z\)bậc 8 

c, \(=2x^3y^3z\)bậc 7 

d, \(=-10x^4yz^3\)bậc 8 

a/ 5x²y (x²y– 4xy² + 7xy)

`=5x^4y^2-20x^3y^3+35x^3y^2`

b/ 3xy² (x²y³ + x 2y – xy² )

`=3x^3y^5+3x^3y^3-3x^2y^4`

c/ 3x(12x² + 4x – 5) + 2x(9x² – 6x + 7)

`=36x^3+12x^2-15x+18x^3-18x^2+14x`

`=54x^3-6x^2-x`

d/ 5x(2x² – 9x – 5) – 9x (x² - 7x – 4)

`=10x^3-45x^2-25x-9x^3+63x^2+36x`

`=x^3+18x^2+11x`

bn có thể ghi theo công thức toán học đc ko

\(5x^2y;x^2y\)

\(3xy^2;\dfrac{2}{3}xy^2;-2xy^2\)

\(\dfrac{4}{3}x^2yz\)

\(7x^2y^2;-\dfrac{1}{5}x^2y^2\)

- 3xy^2, 2/3xy^2, -2xy^2.

- 5x^2

- 7x^2y^2, -1/5x^2y^2.

- 4/3x^2yz.

- x^2y

d) \(4x^2y^2-8xy^2+4y^2=4y^2\left(x^2-2x+1\right)=4y^2\left(x-1\right)^2\)

e) \(x^3y+10x^2y+35xy=xy\left(x^2+10x+35\right)\)

f) \(2x^3-4x^2y+2xy^2-8x=2x\left(x^2-2xy+y^2-4\right)=2x\left[\left(x-y\right)^2-4\right]=2x\left(x-y-2\right)\left(x-y+2\right)\)

g) \(3x^2-9xy-6x+18y=3x\left(x-3y\right)-6\left(x-3y\right)=3\left(x-3y\right)\left(x-2\right)\)

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

d: \(4x^2y^2-8xy^2+4y^2\)

\(=4y^2\left(x^2-2x+1\right)\)

\(=4y^2\left(x-1\right)^2\)

e: \(x^3y+10x^2y+35xy\)

\(=xy\left(x^2+10x+35\right)\)

f: \(2x^3-4x^2y+2xy^2-8x\)

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

\(=2x\left(x-y-2\right)\left(x-y+2\right)\)

g: \(3x^2-9xy-6x+18y\)

\(=3x\left(x-3y\right)-6\left(x-3y\right)\)

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

h: \(x^2y^2-3xy^2+2xy-6y\)

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

\(=y\left(xy+2\right)\left(x-3\right)\)

a, 2xy^2 ( x^3 -3xy - 4 )

b, x^2 - 4x - 4x +16

= x(x-4) - 4(x-4)

= (x-4) (x-4)

Lời giải:

a.

$2x^4y^2-6x^2y^3-8xy^2=2xy^2(x^3-3xy-4)$

b. 

$x^2-8x+16=x^2-2.4.x+4^2=(x-4)^2$

c.

$12x^2-12=12(x^2-1)=12(x-1)(x+1)$

d. 

$5x^2y-20xy+20y=5y(x^2-4x+4)=5y(x-2)^2$
e.

$3x^2y^2-27y^2=3y^2(x^2-9)=3y^2(x-3)(x+3)$

f. 

$8x^3-27y^3=(2x)^3-(3y)^3=(2x-3y)(4x^2+6xy+9y^2)$

g.

$4x^4-8x^3+4x^2=(2x^2)^2-2.2x^2.2x+(2x)^2$

$=(2x^2-2x)^2=[2x(x-1)]^2=4x^2(x-1)^2$
h.

$7x^2y^2-28y^4=7y^2(x^2-4y^2)=7y^2(x-2y)(x+2y)$

$

a: \(4x^3-xy^2\)

\(=x\left(4x^2-y^2\right)\)

\(=x\left(2x-y\right)\left(2x+y\right)\)

b: \(5x^3-10x^2+5x\)

\(=5x\left(x^2-2x+1\right)\)

\(=5x\left(x-1\right)^2\)

c: \(4x^2+24x+36-4y^2\)

\(=4\left(x^2+6x+9-y^2\right)\)

\(=4\left(x+3-y\right)\left(x+3+y\right)\)

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

b) \(5x^3-10x^2+5x=5x\left(x^2-2x+1\right)=5x\left(x-1\right)^2\)

c) \(4x^2+24x+36-4y^2=\left(2x+6\right)^2-4y^2=\left(2x+6-2y\right)\left(2x+6+2y\right)\)

d) \(4x^2y^2-8xy^2+4y^2=4y^2\left(x^2-2x+1\right)=4y^2\left(x-1\right)^2\)

e) \(x^3y+10x^2y+35xy=xy\left(x^2+10x+35\right)\)

f) \(2x^3-4x^2y+2xy^2-8x=2x\left(x^2-2xy+y^2-4\right)=2x\left[\left(x-y\right)^2-4\right]=2x\left(x-y-2\right)\left(x-y+2\right)\)

g) \(3x^2-9xy-6x+18y=3x\left(x-2\right)-9y\left(x-2\right)=3\left(x-2\right)\left(x-3y\right)\)

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

g: \(3x^2-9xy-6x+18y\)

\(=3x\left(x-3y\right)-6\left(x-3y\right)\)

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

h: \(x^2y^2-3xy^2+2xy-6y\)

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

\(=y\left(xy+2\right)\left(x-3\right)\)

a) 20x - 5y

= 5(4x - y)

b) 5x(x - 1)- 3x(x - 1)

= 2x(x - 1)

c) x(x + y) - 6x - 6y

= x(x + y) - (6x + 6y)

= x(x + y) - 6(x + y)

= (x + y)(x - 6)

d) 6x³ - 9x²

= 3x²(2x - 3)

e) 4x²y - 8xy² + 10x²y²

= 2xy(2x - 4y + 5xy)

g) 20x²y - 12x³

= 4x²(5y - 3x)

h) 8x⁴ + 12x²y⁴ - 16x³y⁴

= 4x²(2x² + 3y⁴ - 4xy⁴)

k) 4xy² + 8xyz

= 4xy(y + 2z)

giúp mình vs ạ c ơn nhiều