Persamaan garis yang melalui titik p(2,5) dan sejajar garis 3y-x+5=0 adalah

3y – x + 5 = 0
m = -a/b
= 1/3

y – y1 = m (x – x1)
y – 5 = 1/3 (x – 2) –> kali 3
3y – 15 = x – 2
-x + 3y = 13

3y – x + 5 = 0
3y = x – 5
y = 1/3 x – 5/3

m = 1/3
m1 = m2
m2 = 1/3

melalui (2,5)
y-y1 = m ( x – x1)
y – 5 = 1/3 ( x – 2)
3y – 15 = x – 2
3y – x – 13 = 0