~ Bạn tham khảo ~
`A1,1-8x+16x^2-y^2`
`= 1^2 - 2*4x + (4x)^2 - y^2`
`= (1-4x)^2 - y^2`
`= (1-4x-y)(1-4x+y)`
`A2,x^2-2xy+y^2-z^2`
`= (x-y)^2 - z^2`
`= (x-y-z)(x-y+z)`
`A3,x^2+4xy-16+4y^2`
`= x^2+2*x*2y+(2y)^2-4^2`
`= (x+2y)^2-4^2`
`= (x+2y-4)(x+2y+4)`
`B1, x^2+3x-x-3`
`= x(x+3) - (x+3)`
`= (x-1)(x+3)`
`B2,x^2-y^2+x-y`
`= (x-y)(x+y)+(x-y)`
`= (x-y)(x+y+1)`
`B3,xy+xz+3y+3z`
`= y(x+3)+z(x+3)`
`= (x+3)(y+z)`
`C1,x^2-3x+2`
`= x^2-x-2x+2`
`= x(x-1)-2(x-1)`
`= (x-1)(x-2)`
`C2,x^2-5x+6`
`= x^2-3x-2x+6`
`= x(x-3)-2(x-3)`
`= (x-2)(x-3)`
`C3, x^2+2x-3`
`= x^2+3x-x-3`
`= x(x+3)-(x+3)`
`= (x+3)(x-1)`
