`a)3(2x-1)-5(x-3)+6(3x-4)=24`
`⇔6x-3-5x+15+18x-24=24`
`⇔(6x-5x+18x)+(-3+15-24)=24`
`⇔19x-12=24`
`⇔19x=24+12`
`⇔19x=36`
`⇔x=36/19`
Vậy `x=36/19`
`b)2x(5-3x)+3x(2x-5)-3(x-7)=3`
`⇔10x-6x²+6x²-15x-3x+21=3`
`⇔(10x-15x-3x)+(-6x²+6x²)+21=3`
`⇔-8x+21=3`
`⇔-8x=3-21`
`⇔-8x=-18`
`⇔x=18/8`
`⇔x=9/4`
Vậy `x=9/4`
`c)3x(x+1)-2x(x+2)=1-x`
`⇔3x²+3x-2x²-4x=1-x`
`⇔(3x²-2x²)+(3x-4x)=1-x`
`⇔x²-x=1-x`
`⇔x²-x+x=1`
`⇔x²=1`
`⇔x=±1`
Vậy `x=1` hoặc `x=-1`
`d)2x²+3(x²-1)=5x(x+1)`
`⇔2x²+3x²-3=5x²+5x`
`⇔5x²-3=5x²+5x`
`⇔5x²-5x²-5x=3`
`⇔-5x=3`
`⇔x=-3/5`
Vậy `x=-3/5`
`e)(3x-1)(2x+7)-(x+1)(6x-5)=16`
`⇔6x²+21x-2x-7-(6x²-5x+6x-5)=16`
`⇔6x²+21x-2x-7-6x²+5x-6x+5=16`
`⇔(6x²-6x²)+(21x-2x+5x-6x)+(-7+5)=16`
`⇔18x-2=16`
`⇔18x=16+2`
`⇔18x=18`
`⇔x=18:18`
`⇔x=1`
Vậy `x=1`
`f)(10x+9)x-(5x+2)(2x+3)-8=0`
`⇔10x²+9x-(10x²+15x+4x+6)-8=0`
`⇔10x²+9x-10x²-15x-4x-6-8=0`
`⇔(10x²-10x²)+(9x-15x-4x)-(6+8)=0`
`⇔-10x-14=0`
`⇔-10x=14`
`⇔x=-14/10`
`⇔x=-7/5`
Vậy `x=-7/5`
`g)(3x-5)(7-5x)+(5x+2)(3x-2)=2`
`⇔21x-15x²-35+25x+15x²-10x+6x-4=2`
`⇔(21x+25x-10x+6x)+(-15x²+15x²)-(35+4)=2`
`⇔42x-39=2`
`⇔42x=2+39`
`⇔42x=41`
`⇔x=41/42`
Vậy `x=41/42`
`h)(x-3)(x+7)-(x+5)(x-1)=0`
`⇔x²+7x-3x-21-(x²-x+5x-5)=0`
`⇔x²+7x-3x-21-x²+x-5x+5=0`
`⇔(x²-x²)+(7x-3x+x-5x)+(-21+5)=0`
`⇔0x-16=0`
`⇔0x=16(vô lí)`
Vậy phương trình vô nghiệm
