~ Bạn tham khảo ~
`a, 3x^2+5x-2`
`= 3x^2+6x-x-2`
`= 3x(x+2)-(x+2)`
`= (x+2)(3x-1)`
`b,5x^2+6xy+y^2`
`=5x^2+5xy+xy+y^2`
`=5x(x+y)+y(x+y)`
`=(x+y)(5x+y)`
`c,-14x^2+39x-10`
`=-(14x^2-39x+10)`
`=-(14x^2-4x-35x+10)`
`=-[2x(7x-2)-5(7x-2)]`
`=-(7x-2)(2x-5)`
`d,x^3+2x^2-25x-50`
`=x^3+7x^2-5x^2+10x-35x-50`
`=x^3+7x^2+10x-5x^2-35x-50`
`=x(x^2+7x+10)-5(x^2+7x+10)`
`=(x^2+7x+10)(x-5)`
`=(x^2+2x+5x+10)(x-5)`
`=(x-5)(x+2)(x+5)`
`e,4x^3-14x^2+6x`
`=2x(2x^2-7x+3x)`
`=2x(2x^2-6x-x+3)`
`=2x[2x(x-3)-(x-3)]`
`=2x(x-3)(2x-1)`
`f,x^3+4x^2-29x+24`
`=x^3+7x^2-8x-3x^2-21x+24`
`=x(x^2+7x-8)-3(x^2+7x-8)`
`=(x-3)(x^2+7x-8)`
`=(x-3)(x^2-x+8x-8)`
`=(x-3)[x(x-1)+8(x-1)]`
`=(x-3)(x+8)(x-1)`
`g,x^3+21x^2+134x+240`
`=x^3+18x^2+80x+3x^2+54x+240`
`=x(x^2+18x+80)+3(x^2+18x+80)`
`=(x^2+18x+80)(x+3)`
`=(x^2+8x+10x+80)(x+3)`
`=[x(x+8)+10(x+8)](x+3)`
`=(x+10)(x+8)(x+3)`
