Question

Giúp em câu 2,3

Answer 1

\(2)\left(x-1\right)-\left(2x-1\right)=9-x.\\ \Leftrightarrow x-1-2x+1-9+x=0.\\ \Leftrightarrow0x-9=0. \)

\(\Leftrightarrow0x=9\) (vô lý).

\(3)x\left(x+3\right)^2-3x=\left(x+2\right)^3+1.\\ \Leftrightarrow x\left(x^2+6x+9\right)-3x=x^3+6x^2+12x+8+1.\\ \Leftrightarrow x^3+6x^2+9x-3x-x^3-6x^2-12x-9=0.\\ \Leftrightarrow-6x=9.\\ \Leftrightarrow x=\dfrac{-3}{2}.\)