Persamaan garis yg melalui titik (2,1) dan (7,5) adalah...

[tex] \frac{x-2}{7-2} = \frac{y-1}{5-1} \\ \\ \frac{x-2}{5} = \frac{y-1}{4} \\ \\ 4x-8=5y-5[/tex]

Persamaan Garis Lurus.

(y - y₁) / (y₂ - y₁) = (x - x₁) / (x₂ - x₁)
(y - 1) / (5 - 1) = (x - 2) / (7 - 2)
4(x - 2) = 5(y - 1)
4x - 8 = 5y - 5
4x - 5y = 3
4x - 5y - 3 = 0