Übersicht

`(-1/4)*x = 3/4x-1 || -3/4x `

`-x = -1 || *(-1) `

`x=1 `

Probe:

`(-1/4)*1 = 3/4*1-1 `

`-1/4 = 3/4-1 `✔✔

`=> L={1} `