`5/(x^2-2x+2)-8/(x^2-3x+5)=3`
`⇔5(x^2-3x+5)-8(x^2-2x+2)=3(x^2-3x+5)(x^2-2x+2)`
`⇔5x^2-15x+25-8x^2+16x-16=3(x^4-5x^3+13x^2-16x+10)`
`⇔-3x^4+15x^3-42x^2+49x-31=0`
`⇔3x^4-15x^3+42x^2-49x+31=0`
`⇔3x^2(x-5/2)^2+(93)/4 (x-(98)/(93))^2+31-(2401)/(93)=0`
`⇔3x^2(x-5/2)^2+(93)/4 (x-(98)/(93))^2+(482)/(93)=0`
`⇒`vô nghiệm