`@Mon`
`\text{ Bài 4:}`
`a)3(2x-3)+2(2-x)=-3`
`<=>6x-9+4-2x=-3`
`<=>4x-2=0`
`<=>x=\frac{1}{2}`
`b)x(5-2x)+2x(x-1)=13`
`<=>5x-2x^2+2x^2-2x=13`
`<=>3x=13`
`<=>x=\frac{13}{3}`
`c)5x(x-1)-(x+2)(5x-7)=6`
`<=>x^2-5x-(5x^2+3x-14)=6`
`<=>-8x=-8`
`<=>x=1`
`d)3x(2x+3)-(2x+5)(3x-2)=8`
`<=>6x^2+9x-(6x^2+11x-10)=8`
`<=>-2x=-2`
`<=>x=1`
`e)2(5x-8)-3(4x-5)=4(3x-4)+11`
`<=>10x-16-12x+15=12x-16+11`
`<=>-14x=-4`
`<=>x=\frac{2}{7}`
`f)2x(6x-2x^2)+3x^2(x-4)=8`
`<=>12x^2-4x^3+3x^3-12x^2=8`
`<=>-x^3=8`
`<=>-x^3=2^3`
`<=>x=-2`
`\text{ Bài 5:}`
`a)2(3x-1)(2x+5)-6(2x-1)(x+2)=-6`
`<=>2(6x^2+13x-5)-6(2x^2+3x-2)=-6`
`<=>12x^2+26x-10-12x^2-18x+12+6=0`
`<=>8x+8=0`
`<=>8x=-8`
`<=>x=-1`
`b)2x(x^2-2)+x^2(x-2x)-x^2=-12`
`<=>2x^3-4x+x^2-2x^2-x^2=-12`
`<=>-4x=-12`
`<=>x=(-12):(-4)`
`<=>x=3`
`c)4(2-x)+x(x+6)=x^2`
`<=>8-4x+x^2+6x-x^2=0`
`<=>2x+8=0`
`<=>2x=-8`
`<=>x=(-8):2`
`<=>x=-4`
`d)4x(x-1)-3(x^2-5)-x^2=-7`
`<=>4x^2-4x-3x^2+15-x^2=-7`
`<=>-4x+15=-7`
`<=>-4x=-7-15`
`<=>-4x=-22`
`<=>x=(-22):(-4)`
`<=>x=\frac{11}{2}`
