$\frac{(7x+1)(x-2)}{10}$+$\frac{2}{5}$= $\frac{(x-2)^{2}}{5}$+$\frac{(x-1)(x-3)}{2}$

` Hiển `

` \frac{(7x+1)(x-2)}{10} + 2/5 = (x-2)^2/5 + \frac{(x-1)(x-3)}{2} `

` => \frac{(7x+1)(x-2)+4}{10} = \frac{2(x-2)^2+5(x-1)(x-3)}{10} `

` => (7x^2 - 13x + 2)/10 = (7x^2-28x+23)/10 `

` => 7x^2 - 13x + 2 = 7x^2 - 28x + 23 `

` => 7x^2 - 13x - 7x^2 + 28x = 23 - 2 `

` => 15x = 21 `

` => x=21/15 = 7/5 `

`\frac{(7x+1).(x-2)}{10}+\frac{2}{5}=\frac{(x-2)^2}{5}+\frac{(x-1).(x-3)}{2}`

`<=>\frac{(7x+1).(x-2)}{10}+\frac{4}{10}=\frac{2.(x-2)^2}{10}+\frac{5.(x-1).(x-3)}{10}`

`<=>\frac{(7x+1).(x-2)+4}{10}=\frac{2.(x-2)^2+5.(x-1).(x-3)}{10}`

`<=>(7x+1).(x-2)+4=2.(x-2)^2+5.(x-1).(x-3)`

`<=>7x.x-7x.2+1.x-1.2+4=2.(x^2-4x+4)+5.(x.x-x.3-1.x+1.3)`

`<=>7x^2-14x+x-2+4=2x^2-8x+8+5x^2-15x-5x+15`

`<=>7x^2-13x+2=7x^2-28x+23`

`<=>7x^2-7x^2-13x+28x=23-2`

`<=>15x=21`

`<=>x=\frac{21}{15}`

`<=>x=\frac{7}{5}`

Vậy phương trình có tập nghiệm là `S={\frac{7}{5}}`