a,
Ta có:
`4x^3-8x^2+13x-5`
`=4x^3-2x^2-6x^2+3x+10x-5`
`=2x^2(2x-1)-3x(2x-1)+5(2x-1)`
`=(2x-1)(2x^2-3x+5)`
`=>(4x^3-8x^2+13x-5)/(2x-1)=((2x-1)(2x^2-3x+5))/(2x-1)=2x^2-3x+5`
b,
`2x^3-4x^2+2x`
`=2x^3-2x^2-2x^2+2x`
`=2x^2(x-1)-2x(x-1)`
`=2x(x-1)(x-1)`
`=2x(x-1)^2`
c,
`x^2-4x+4-25y^2`
`=(x-2)^2-(5y)^2`
`=(x-5y-2)(x+5y-2)`