Đáp án+Giải thích các bước giải:
a)
`3(x-2)(x+3)-x(3x+1)=2`
`<=>3(x^2+3x-2x-6)-x(3x+1)=2`
`<=>3(x^2+x-6)-x(3x+1)=2`
`<=>3x^2+3x-18-3x^2-x=2`
`<=>3x^2+3x-3x^2-x=2+18`
`<=>2x=20`
`<=>x=10`
Vậy `S={10}`
b)
`(2x+1)(1-2x)+(2x-1)^2=22`
`<=>(2x+1)(1-2x)+(1-2x)^2=22`
`<=>(1-2x)(1-2x+2x+1)=22`
`<=>2(1-2x)=22`
`<=>1-2x=11`
`<=>-2x=10`
`<=>x=-5`
Vậy `S={-5}`
c)
`(x+4)(x^2-4x+16)-x(x-5)(x+5)=264`
`<=>x^3+4^3-x(x^2-25)=264`
`<=>x^3+64-x^3+25x=264`
`<=>x^3-x^3+25x=264-64`
`<=>25x=200`
`<=>x=8`
Vậy `S={8}`
