Bài 1
1) \(5\left(x-y\right)-y\left(x-y\right)\)
\(=\left(x-y\right)\left(5-y\right)\)
2) \(x\left(y+1\right)+8\left(y+1\right)\)
\(=\left(y+1\right)\left(x+8\right)\)
3) \(3x\left(x-2\right)+5\left(2-x\right)\)
\(=3x\left(x-2\right)-5\left(x-2\right)\)
\(=\left(x-2\right)\left(3x-5\right)\)
4) \(7x\left(x-y\right)-\left(y-x\right)\)
\(=7x\left(x-y\right)+\left(x-y\right)\)
\(=\left(x-y\right)\left(7x+1\right)\)
5) \(5x\left(x-1\right)-15x\left(1-x\right)\)
\(=5x\left(x-1\right)+15x\left(x-1\right)\)
\(=\left(x-1\right)\left(5x+15x\right)\)
\(=\left(x-1\right)5x\left(x+3\right)\)
6) \(10x\left(x-y\right)-6xy\left(y-x\right)\)
\(=10x\left(x-y\right)+6xy\left(x-y\right)\)
\(=\left(x-y\right)\left(10x+6xy\right)\)
\(=\left(x-y\right)2x\left(5+3y\right)\)
Bài 2
1) \(2y\left(x+2\right)-3x-6\)
\(=2y\left(x+2\right)-3\left(x+2\right)\)
\(=\left(x+2\right)\left(2y-3\right)\)
2) \(3\left(x+4\right)-x^2-4x\)
\(=3\left(x+4\right)-x\left(x+4\right)\)
\(=\left(x+4\right)\left(3-x\right)\)
3) \(2\left(x+5\right)-x^2-5x\)
\(=2\left(x+5\right)-x\left(x+5\right)\)
\(=\left(x+5\right)\left(2-x\right)\)
4) \(x^2+6x-x\left(x+6\right)\)
\(=x\left(x+6\right)-x\left(x+6\right)\)
\(=0\)
5) \(x\left(x+y\right)-5x-5y\)
\(=x\left(x+y\right)-5\left(x+y\right)\)
\(=\left(x+y\right)\left(x-5\right)\)
6) \(x\left(x-y\right)+2x-2y\)
\(=x\left(x-y\right)+2\left(x-y\right)\)
\(=\left(x-y\right)\left(x+2\right)\)
7) \(x^2-xy+x-y\)
\(=x\left(x-y\right)+\left(x-y\right)\)
\(\left(x-y\right)\left(x+1\right)\)
8) \(\left(x+1\right)y-2x-2\)
\(=y\left(x+1\right)-2\left(x+1\right)\)
\(=\left(x+1\right)\left(y-2\right)\)
9) \(9x^3-9x^2y-4x+4y\)
\(=9x^2\left(x-y\right)-4\left(x-y\right)\)
\(=\left(x-y\right)\left(9x^2-4\right)\)
Bài `1`
`1, 5(x-y)-y(x-y)`
`=(x-y)(5-y)`
`2,x(y+1)+8(y+1)`
`=(y+1)(x+8)`
`3,3x(x-2)+5(2-x)`
`=3x(x-2) -5(x-2)`
`=(x-2)(3x-5)`
`4,7x(x-y)-(y-x)`
`=7x(x-y) +(x-y)`
`=(x-y)(7x+1)`
`5,5x(x-1)-15x(1-x)`
`= 5x(x-1) +15x(x-1)`
`=(x-1)(5x+15x)`
`6,10x(x-y)-6y(y-x)`
`=10x(x-y) +6y(x-y)`
`= (x-y)(10x+6y)`
`= 2(x-y)(5x+3y)`
