`1)4x(x-5)-(x-1)(4x-3)=5`
`⇔4x²-20x-(4x²-3x-4x+3)=5`
`⇔4x²-20x-4x²+3x+4x-3=5`
`⇔-13x-3=5`
`⇔-13x=5+3`
`⇔-13x=8`
`⇔x=-8/13`
Vậy `x=-8/13`
`2)(3x-4)(x-2)=3x(x-9)-3`
`⇔3x²-6x-4x+8=3x²-27x-3`
`⇔3x²-6x-4x-3x²+27x=-3-8`
`⇔17x=-11`
`⇔x=-11/17`
Vậy `x=-11/17`
`3)(x-5)(x-4)-(x+1)(x-2)=7`
`⇔x²-4x-5x+20-(x²-2x+x-2)=7`
`⇔x²-4x-5x+20-x²+2x-x+2=7`
`⇔-8x+22=7`
`⇔-8x=7-22`
`⇔-8x=-15`
`⇔x=15/8`
Vậy `x=15/8`
`4)5x(x-3)=(x-2)(5x-1)-5`
`⇔5x²-15x=5x²-x-10x+2-5`
`⇔5x²-15x-5x²+x+10x=2-5`
`⇔-4x=-3`
`⇔x=3/4`
Vậy `x=3/4`
`5)(x-5)(x-1)=(x-1)(x-2)`
`⇔(x-5)(x-1)-(x-1)(x-2)=0`
`⇔(x-1)(x-5-x+2)=0`
`⇔-3(x-1)=0`
`⇔x-1=0`
`⇔x=1`
Vậy `x=1`
`6)6(x-3)(x-4)-6x(x-2)=4`
`⇔(6x-18)(x-4)-6x(x-2)=4`
`⇔6x²-24x-18x+72-6x²+12x=4`
`⇔6x²-24x-18x-6x²+12x=4-72`
`⇔-30x=-68`
`⇔x=68/30`
`⇔x=34/15`
Vậy `x=34/15`
