Question

x+1/2=x/3

1-2x/9=1/1-2x

4/5=12/x=y/20=8(y-z)/x

Answer 1

1, \(\frac{x+1}{2}=\frac{x}{3}\)

<=> 3(x+1)=2x

<=> 3x+3-2x=0

<=> x+3=0

<=> x=-3

2, \(\frac{1-2x}{9}=\frac{1}{1-2x}\left(x\ne\frac{1}{2}\right)\)

<=> (1-2x)²=9

<=> \(\orbr{\begin{cases}1-2x=3\\1-2x=-3\end{cases}\Leftrightarrow\orbr{\begin{cases}2x=-2\\2x=4\end{cases}\Leftrightarrow}\orbr{\begin{cases}x=-1\\x=2\end{cases}}\left(tmđk\right)}\)

Vậy x={-1;2}