persamaan garis lurus melalui titik (1,4) dan (2, -1)

Garis Lurus.

[tex]\displaystyle \frac{y-y_1}{y_2-y_1}=\frac{x-x_1}{x_2-x_1}\\ \frac{y-4}{-1-4}=\frac{x-1}{2-1}\\ -5(x-1)=y-4\\ 5x+y-9=0[/tex]