`#tnvt`
`a)(x+4)^2-(x+1)(x-1)=16`
`<=>x^2+8x+16-x^2+1=16`
`<=>8x=-1`
`<=>x=-1/8`
Vậy `x=-1/8`
`b)2x(x-5)-x(3+2x)=26-2x`
`<=>2x^2-10x-3x-2x^2+2x=26`
`<=>-11x=26`
`<=>x=-26/11`
Vậy `x=-26/11`
`c)(2x-1)^3+12(x-1)(x+1)=14x-13`
`<=>8x^3-12x^2+6x-1+12(x^2-1)-14x=-13`
`<=>8x^3-12x^2-8x+12x^2-12=-12`
`<=>8x^3-8x=0`
`<=>8x(x^2-1)=0`
`<=>8x(x-1)(x+1)=0`
`<=>[(x=0),(x=+-1):}`
Vậy `x\in{0;+-1}`