k cho tui nha

a: =(x+6)(x-1)

n: \(=4x^4+36x^2+81-36x^2\)

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

Ta có x 2 – 7x + 10

= x 2 – 2x – 5x + 10

= x(x – 2) – 5(x – 2) = (x – 5)(x – 2)

Đáp án cần chọn là: B

\(x^3-x^2+7x-7=x^2\left(x-1\right)+7\left(x-1\right)=\left(x-1\right)\left(x^2+7\right)\)

a: =5x(x-y)-7(x-y)

=(x-y)(5x-7)

b: =x(x+2y)+(x+2y)

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

c; =(x-3)^2-9y^2

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

a

\(5x^2-5xy+7y-7x\\ =5x\left(x-y\right)+7\left(y-x\right)\\ =5x\left(x-y\right)-7\left(x-y\right)\\ =\left(5x-7\right)\left(x-y\right)\)

b

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

c

\(x^2-6x-9y^2+9\\ =x^2-6x+9-\left(3y\right)^2\\ =x^2-2.x.3+3^2-\left(3y\right)^2\\ =\left(x-3\right)^2-\left(3y\right)^2\\ =\left(x-3-3y\right)\left(x-3+3y\right)\)

Ta có:  x 2 + 6 x + 9 = x 2 + 2 . x . 3 + 3 2 = ( x + 3 ) 2 .

Ta có:  x 2 + 6 x + 9 = x 2 + 2 . x . 3 + 3 2 = ( x + 3 ) 2 .

a. \(x^2\) - 9y²

= (\(x\))² - (3y)²

= (\(x\) - 3y)(\(x\) + 3y)

x² - 9y² = x² - (3y)²= (x - 3y)(x + 3y)

B. 7\(x\).(\(x\) - y) + 3\(x\) - 3y

= 7\(x\).(\(x\) -y) + 3.(\(x\) - y)

= (\(x\) - y)(7\(x\) + 3)

a) \(\left(x^2-7x+12\right).\left(x^2-15x+56\right)-60\)

\(=\left(x-3\right)\left(x-4\right)\left(x-7\right)\left(x-8\right)-60\)

b) \(x^4+2000x^2+1999x+2000\)

\(=\left(x^2-x+2000\right)\left(x^2+x+1\right)\)

\(=\left(x^2+x-1\right)^2+1999\left(x^2+x+1\right)+1\)

hình như Thành lộn đề rồi đấy ạ, ý mình là phân tích thành nhân tử á

b) \(x^4+2000x^2+1999x+2000\)

\(=x^4-x+2000x^2+2000x+2000\)

\(=x\left(x^3-1\right)+2000\left(x^2+x+1\right)\)

\(=x\left(x-1\right)\left(x^2+x+1\right)+2000\left(x^2+x+1\right)\)

\(=\left(x^2+x+1\right)\left(x^2-x-2000\right)\)