đề bài yêu cầu là "giải các phương trình sau " ạ
a)
\(\left|2-3x\right|=-1\) (vô lí vì \(\left|2-3x\right|\ge0\) )
b)
`3x-2,42+0,8=3,38-0,2x`
`<=>3x+0,2x=3,38+2,42-0,8`
`<=>3,2x=5`
`<=>x=25/16`
c)
\(\dfrac{3}{x-1}+\dfrac{2}{x^2+x+1}=\dfrac{3x^2}{x^3-1}\left(x\ne1\right)\)
\(< =>\dfrac{3}{x-1}+\dfrac{2}{x^2+x+1}=\dfrac{3x^2}{\left(x-1\right)\left(x^2+x+1\right)}\)
\(< =>\dfrac{3\left(x^2+x+1\right)}{\left(x-1\right)\left(x^2+x+1\right)}+\dfrac{2\left(x-1\right)}{\left(x-1\right)\left(x^2+x+1\right)}=\dfrac{3x^2}{\left(x-1\right)\left(x^2+x+1\right)}\)
suy ra
`3x^2 +3x+3+2x-2=3x^2`
`<=>3x^2 -3x^2 +3x+2x=-3+2`
`<=>5x=-1`
`<=>x=-1/5(tmđk)`
