Đáp án + giải thích các bước giải:
`(5x^2-7x+3)-(x^2-x+1)=4x`
`->5x^2-7x+3-x^2+x-1=4x`
`->4x^2-6x+2=4x`
`->2x^2-3x+1=2x`
`->2x^2-3x-2x+1=0`
`->2x^2-5x+1=0`
`->x^2-5/2 x +1/2=0`
`->x^2- 2. x. 5/4 +25/16-17/16=0`
`->x(x-5/4)-5/4(x-5/4)=17/16`
`->(x-5/4)^2=17/16`
`->`\(\left[ \begin{array}{l}x-\dfrac{5}{4}=\dfrac{\sqrt{17}}{4}\\x-\dfrac{5}{4}=\dfrac{-\sqrt{17}}{4}\end{array} \right.\)
`->`\(\left[ \begin{array}{l}x=\dfrac{\sqrt{17}+5}{4}\\x=\dfrac{-\sqrt{17}+5}{4}\end{array} \right.\)
Vậy `x=\frac{\sqrt{17}+5}{4};\frac{-\sqrt{17}+5}{4}`
