Respuesta :

[tex]\begin{gathered} ty-qy+p=r \\ ty-qy+p-p=r-p \\ ty-qy=r-p \\ y(t-q)=r-p \\ \frac{y(t-q)}{t-q}=\frac{r-p}{t-q} \\ y=\frac{r-p}{t-q} \end{gathered}[/tex]