bạn tham khảo nha

a)  85 .12,7 + 5.3.12,7 = 12,7 . ( 85 + 5.3 ) = 12,7 . (85+15) = 12,7 . 100 = 1270

b)  52.143 - 52.39 - 8.26 = 52.143 - 52.39 - 4.2.26 = 52.143 - 52.39 - 4.52 = 52.( 143 -39 - 4 ) = 52 . 100 = 5200

phân tích :

5x - 20y = 5 .(x - 4y)

5x(x-1)-3x.(x-1) = (x-1).(5x-3x) = 2x(x-1)  hoặc 5x(x-1)-3x(x-1) = x(x-1)(5-3) = 2x(x-1)

x.(x+y)-5x-5y = x(x+y) - 5 (x+y) = (x+y)(x-5)

a, \(\left(3x-6y\right)x+y\left(x-2y\right)=\left(3x+y\right)\left(x-2y\right)\)

b, \(3\left(x-y\right)-5x\left(y-x\right)=\left(3+5x\right)\left(x-y\right)\)

c, \(\dfrac{2}{5}x\left(y-1\right)+\dfrac{2}{5}y\left(1-y\right)=\left(\dfrac{2}{5}x-\dfrac{2}{5}y\right)\left(y-1\right)=\dfrac{2}{5}\left(x-y\right)\left(y-1\right)\)

d, \(x\left(x-1\right)-y\left(1-x\right)=\left(x+y\right)\left(x-1\right)\)

a) \(5x-20y\)

\(=5\left(x-4y\right)\)

b) \(5x\left(x-1\right)-3x\left(x-1\right)\)

\(=2x\left(x-1\right)\) 

c) \(x\left(x+y\right)-5x-5y\)

\(=x\left(x+y\right)-5\left(x+y\right)\)

\(=\left(x-5\right)\left(x+y\right)\)

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

= ( 5x - 3x ) ( x - 1 )

= 2x ( x - 1 )

c ) x ( x + y ) - 5 x - 5y

= x ( x + y ) - 5 ( x + y )

= ( x - 5 ) (x + y )

d ) x ^ 2 + xy + x

= x ( x + y + 1 )

e ) x ( x - y ) + y ( y - x )

= x ( x - y ) - y ( x - y )

= ( x - y ) ( x -y )

= ( x - y ) ²

a, 5x(x-1)-3x(x-1)=(5x-3x)(x-1)=2x(x-1)

b, x(x+y)-5x-5y=x(x+y)-5(x+y)=(x-5)(x+y)

c, x²+xy+x=x(x+y+1)

d, x(x-y)+y(y-x)=x(x-y)-y(x-y)=(x-y)(x-y)=(x-y)²

b)5x(x-1)-3x(x-1)=x(x-1).(5-3)=x(x-1).2

c)x(x+y)-5x-5y=x(x+y)-(5x+5y)=x(x+y)-[5(x+y)[=(x+y).(x-5)

d)x^2+xy+x=x(x+y+1)

e)x(x-y)+y(y-x)=x(x-y)-(x-y).y=(x-y).(x-y)

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

\(a,14x^2y-21xy^2+28x^2y^2=7xy\left(x-3y+4xy\right)\\ b,x\left(x+y\right)-5x-5y=x\left(x+y\right)-5\left(x+y\right)=\left(x+y\right)\left(x-5\right)\\ c,10x\left(x-y\right)-8\left(y-x\right)=10x\left(x-y\right)+8\left(x-y\right)=\left(x-y\right)\left(10x+8\right)=2\left(x-y\right)\left(5x+4\right)\)

\(d,\left(3x+1\right)^2-\left(x+1\right)^2=\left(3x+1-x-1\right)\left(3x+1+x+1\right)=2x\left(4x+2\right)=4x\left(2x+1\right)\)\(e,x^3+y^3+z^3-3xyz=\left(x+y+z\right)\left(x^2+y^2+z^2-xy-yz-zx\right)+3xyz-3xyz=\left(x+y+z\right)\left(x^2+y^2+z^2-xy-yz-zx\right)\)

a: =5(2x+3y)

d: =(x+1-y)(x+1+y)