fungsi garis g adalah?

Titik potong thp sb y : y = a = 1/2
Titik potong thp sb x : x = b = 2
Maka persamaan garisnya :
ax + by = ab
1/2 x + 2y = 1/2 . 1
1/2 x + 2y = 1
2y = -1/2 x + 1
y = -1/4 x + 1/2

Cara lain : (0, 1/2) dan (2, 0)
(y2 - y1)/(x2 - x1) = (y - y1)/(x - x1)
(0 - 1/2)/(2 - 0) = (y - 1/2)/(x - 0)
(-1/2) / 2 = (y - 1/2) / x
2(y - 1/2) = -1/2 x
2y - 1 = -1/2 x
2y = -1/2 x + 1
y = -1/4 x + 1/2