a)\(\dfrac{x^2-4xy+4y^2}{xy-2y^2}\)

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

=\(\dfrac{\left(x-2y\right)^2}{y\left(x-2y\right)}\)

=\(\dfrac{x-2y}{y}\)

b)\(\dfrac{x^3-36x}{x^2+6x}\)

=\(\dfrac{x\left(x^2-6^2\right)}{x\left(x+6\right)}\)

=\(\dfrac{x\left(x+6\right)\left(x-6\right)}{x\left(x+6\right)}\)

= \(x-6\)

#Fiona 

Chúc bạn học tốt !

a) Xem lại đề

b) x³ - 4x²y + 4xy² - 9x

= x(x² - 4xy + 4y² - 9)

= x[(x² - 4xy + 4y² - 3²]

= x[(x - 2y)² - 3²]

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

c) x³ - y³ + x - y

= (x³ - y³) + (x - y)

= (x - y)(x² + xy + y²) + (x - y)

= (x - y)(x² + xy + y² + 1)

d) 4x² - 4xy + 2x - y + y²

= (4x² - 4xy + y²) + (2x - y)

= (2x - y)² + (2x - y)

= (2x - y)(2x - y + 1)

e) 9x² - 3x + 2y - 4y²

= (9x² - 4y²) - (3x - 2y)

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

= (3x - 2y)(3x + 2y - 1)

f) 3x² - 6xy + 3y² - 5x + 5y

= (3x² - 6xy + 3y²) - (5x - 5y)

= 3(x² - 2xy + y²) - 5(x - y)

= 3(x - y)² - 5(x - y)

= (x - y)[(3(x - y) - 5]

= (x - y)(3x - 3y - 5)

đề bài là rút gọn à

a: =>A-B=3x^2y-4xy^2+x^2y-2xy^2=4x^2y-6xy^2

b: =>B-A=-7xy^2+8x^2y-5xy^2+6x^2y=-12xy^2+14x^2y

=>A-B=12xy^2-14x^2y

c: =>B-A=8x^2y^3-4x^3y-3x^2y^3+5x^3y^2=5x^2y^3+x^3y^2

=>A-B=-5x^2y^3-x^3y^2

d: =>A-B=2x^2y^3-7x^3y+6x^2y^3+3x^3y^2=8x^2y^3-7x^3y+3x^3y^2

a, A = 27x³ + 54x² + 36x + 4

=> A = (3x)³ + 2 . 3 . 9x² + 3 . 3x . 4 + 8 - 4

=> A = [(3x)³ + 2 . 3 . (3x)² + 3 . 3x . 2² + 2³] - 4

=> A = (3x + 2)³ - 4

Thay x = -2002 vào A ta có: A = (3x + 2)³ - 4 

=> A = [3 x (-2002) + 2]³ - 4 = [6006 + 2]³ - 4 = 6008³ - 4

b, B = 2x² + 4x + xy + 2y

=> B = 2x(x + 2) + y(x + 2)

=> B = (x + 2)(2x + y)

Thay x = 88; y = -76 vào B

=> B = (88 + 2)[2 . 88 + (-76)]

=> B = 90 . [176 + (-76)] = 90 . 100 = 9000

làm ơn giúp e vs

\(1,=\left(x-2\right)\left(5-y\right)\\ 2,=2\left(x-y\right)^2-z\left(x-y\right)=\left(x-y\right)\left(2x-2y-z\right)\\ 3,=5xy\left(x-2y\right)\\ 4,=3\left(x^2-2xy+y^2-4z^2\right)=3\left[\left(x-y\right)^2-4z^2\right]\\ =3\left(x-y-2z\right)\left(x-y+2z\right)\\ 5,=\left(x+2y\right)^2-16=\left(x+2y-4\right)\left(x+2y+4\right)\\ 6,=-\left(6x^2-3x-4x+2\right)=-\left(2x-1\right)\left(3x-2\right)\\ 7,=\left(2x+y\right)\left(2x+y+x\right)=\left(2x+y\right)\left(3x+y\right)\\ 8,=\left(x-y\right)\left(x+5\right)\\ 9,=\left(x+1\right)^2-y^2=\left(x-y+1\right)\left(x+y+1\right)\\ 10,=\left(x^2-9\right)x=x\left(x-3\right)\left(x+3\right)\\ 11,=\left(x-2\right)\left(y+1\right)\\ 12,=\left(x-3\right)\left(x^2-4\right)=\left(x-3\right)\left(x-2\right)\left(x+2\right)\\ 13,=3\left(x+y\right)-\left(x+y\right)^2=\left(x+y\right)\left(3-x-y\right)\)