bài 1, bạn tự làm nhé đặt chia đi bạn

bài 2

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

\(b,=a^2-2a-5a+10=a\left(a-2\right)-5\left(a-2\right)=\left(a-2\right)\left(a-5\right)\)

 1a) 8xy(8-12x+6x*x-x*x*x)

 chú thích   x*x là x bình phương

                 x*x*x là x lập phương

2. a) 3x (x-5)- (x-1)(2+3x)=30

      3x*x-15x-2x-3x*x+2+3x=30

           14x=28

           x=2 

  b) (x+2)(x-3)-(x-2)(x+5)=0

     x*x-3x+2x-6-x*x-5x+2x+10=0

       2x=-4

       x=-2

  còn mấy  bài còn lại mình không biết

a) \(2x^2\left\{x^2+5x+6\right\}\)=\(2x^4+10x^3+12x^2\)

b) \(15x^2y^4:10x^2y\)=\(\frac{3}{2}y^3\)

c) \(\left\{16x^3y^2+20x^2y^3-8xy\right\}:4xy\)=\(4x^2y+5xy^2-2\)

1.

\(3x^2-3xy+5x-5y\)

\(=\left(3x^2-3xy\right)+\left(5x-5y\right)\)

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

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

2.

\(x^2+y^2+2xy-x-y\)

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

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

\(=\left(x+y\right).\left(x+y-1\right)\)

3.

\(x^2-xy+x-y\)

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

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

\(=\left(x-y\right).\left(x+1\right)\)

4.

\(x^2-2xy+y^2-z^2+2zt-t^2\)

\(=\left(x^2-2xy+y^2\right)-\left(z^2-2zt+t^2\right)\)

\(=\left(x-y\right)^2-\left(z-t\right)^2\)

\(=\left[x-y-\left(z-t\right)\right].\left[x-y+\left(z-t\right)\right]\)

\(=\left(x-y-z+t\right).\left(x-y+z-t\right)\)

6.

\(2x^2-8x+6\)

\(=2.\left(x^2-4x+3\right)\)

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

\(=2.\left[\left(x^2-3x\right)-\left(x-3\right)\right]\)

\(=2.\left[x.\left(x-3\right)-\left(x-3\right)\right]\)

\(=2.\left(x-3\right).\left(x-1\right)\)

Chúc bạn học tốt!

\(y^2\left(1+y\right)+\left(y+1\right)+1\)

\(\Leftrightarrow\left(y+1\right)\left(y^2+1\right)+1\)

vay \(\left(y^2+y^3+2+y\right)\div\left(y^2+1\right)\)dư 1

\(\)

Mình sửa: Bài 1
2)x²+3x-15

a) x² + 6x + 9 = x² + 2 . x . 3 + 3² = (x + 3)²

b) 10x – 25 – x² = -(-10x + 25 +x²) = -(25 – 10x + x²)

                         = -(5² – 2 . 5 . x – x²) = -(5 – x)²

c) 8x³ - 1/8 = (2x)³ – (1/2)³ = (2x - 1/2)[(2x)² + 2x . 12 + (1/2)²]

                    ^{= (2x - 1/2)(4x2 + x + 1/4)} 

d)1/25x² – 64y² = (1/5x)2(1/5x)2- (8y)² = (1/5x + 8y)(1/5x - 8y)

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

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

\(x^4-4x^3-x^2y^2+4x^2\)

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

\(=x^2\left[\left(x-2\right)^2-y^2\right]\)

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

\(5x-5y-x^2+2xy-y^2\)

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

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

Đề câu thứ hai hình như sai, mình tính không ra nên sửa chỗ -2xy thành +2xy, không biết ổn không.

Chúc bạn học giỏi!