## Todo
- [ ] spaced repetition
- [ ] kung-fu
## I did
### Helped praly
$$
\begin{align} (S) &\iff \begin{cases}x &+y&+2z &= 5\\ x &- y &- z &= 5\\ x &&+ z &=  3\end{cases}  \\[1em]
&\iff \begin{cases}x&+y&+2z &= 5 \\
                 &-y &-2z &= 2 && L_{2} \leftarrow L_{2}-L_{3}\\
                x &  &+z &= 3\end{cases} \\[1em]
&\iff \begin{cases}x &+y &+2z &= 5 \\
                  &-y &-2z &= 2 \\
                  &   &z   &= -4&& L_{3} \leftarrow - L_{1} - L_{2} + L_{3}\end{cases} \\[1ex]
&\iff \begin{cases}x &+y&&=13 \\
                  &y &   &= 6 \\
                  &  &  z&=-4\end{cases} \\[1ex]
&\iff \begin{cases}x=7 \\
                y=6 \\
                z=-4\end{cases}
\end{align}
$$

## Devoirs
> [!smalltodo] Devoirs
> ```dataview
> TABLE difficulty as "", due as "date", title as "description", file.etags as "tags"
> FROM #devoir
> WHERE contains(due, date(this.file.name))
> ```
> > [!done]- Devoirs faits
> > ```dataview
> > TABLE difficulty as "", due as "date", title as "description"
> > FROM #devoir-fait
> > WHERE contains(due, date(this.file.name))
> > ```

> [!smallquery] anniversaires `=this.file.name`
> ```dataview
> TABLE title, anniv
> FROM #personne 
> WHERE contains(this.file.name, anniv)
> ```
## I am gratefull to