`i)2x^3+5x^2-12x=0`
`<=>x(2x^2+8x-3x-12x)=0`
`<=>x(2x-3)(x+4)=0`
`<=>[(x=0),(x=3/2),(x=-4):}`
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`g)x^3-7x(x-2)=8`
`<=>x^3-8-7x(x-2)=0`
`<=>(x-2)(x^2+2x+4)-7x(x-2)=0`
`<=>(x-2)(x^2+2x+4-7x)=0`
`<=>(x-2)(x^2-5x+4)=0`
`<=>(x-2)(x-1)(x-4)=0<=>[(x=2),(x=1),(x=4):}`
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`h)3x(x-1)=x^2-2x+1`
`<=>3x(x-1)-(x-1)^2=0`
`<=>(x-1)(3x-x+1)=0`
`<=>(x-1)(2x+1)=0<=>[(x=1),(x=-1/2):}`
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