Đáp án:
`↓↓`
Giải thích các bước giải:
` a )`
`1x -3 + 2= 5x -1 +x`
`⇔1x -3 +2 =6x -1 `
`⇔1x-6x =-1 +3-2`
`⇔ -5x = 0`
`⇔x = 0:5`
`⇔x =0`
`b)`
`(x-2)(x+5)-7x=(x-1)(x+3)`
`⇔ x^2+ 5x-2x-10-7x=x^2+3x-x-3`
`⇔x^2+ 5x-2x-7x-x^2-3x+x= -3+10`
`⇔-7x=7`
`⇔x=7=-1`
`c)`
`2x^2-1 =0`
`⇔2x^2=1`
`⇔x^2 =1/2`
`⇔x= √1 ≈0.7`
`d)`
`4x^2 -17x +4=0`
`⇔4x^2 -4x-1 x+4=0`
`⇔(4x^2-1 x)-(4x-4)=0`
`⇔4x(x-1)-4(x-1)=0`
`⇔(x-1)(4x-4)=0`
`<=>`\(\left[ \begin{array}{l}x-1=0\\4x-4=0\end{array} \right.\)
`<=>`\(\left[ \begin{array}{l}x=1\\4x=4\end{array} \right.\)
`⇔x=4:4`
`⇔x=1`
`e)`
`x^3 +9x^2 +26x +24= 0`
`⇔(x+3)^3=0`
`⇔x+3=0`
`⇔x=-3`
`f)`
`(4x +3)^2 =x^2+2x+1`
`⇔(4x+3)^2-(x+1)^2=0`
`⇔(4x+3-x+1)(4x+3+x-1)=0`
`<=>`\(\left[ \begin{array}{l}3x=-4\\5x=-2\end{array} \right.\)
`<=>x=3/-4=-3/4` hoặc `<=>x=-2/5 .`
