\(a\left(x-1\right)+b\left(1-x\right)=a\left(x-1\right)-b\left(x-1\right)=\left(x-1\right)\left(a-b\right)\)

a) ( x + 1) + b ( 1 - x )

= ( x + 1 ) - b( x-   1 )

= ( 1 - b )( x- 1 )

**** 

a(x-1) + b(1-x)

= a(x-1) - b(x-1)

= (a-b)(x-1)

Nhấn đúng cho mk nha!!!!!!!!!

x³-2x²-5x=x(x²-2x-5)

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

\(x^2-1=\left(x+1\right)\left(x-1\right)\)(Nhớ k cho mình với nhé!)

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

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

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

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

\(\left(x-y\right)\times\left(x-y\right)\)

ta có:

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

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

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

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

Violympic nên chắc khỏi cần cách làm nhỉ :

1) 3

2) 2 

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

a, y(x+1+8+8)

y(x+17)

b, x(x-1)

a) xy + x + 8y + 8

= x ( y + 1 ) + 8 ( y + 1 )

= ( y + 1 ) . ( x + 8 )

b) x² - 1  

= x² - x + x - 1 

= x ( x - 1 ) + ( x - 1 )

= ( x - 1 ) . ( x + 1 )