Question

Sebuah garis mempunya gradien 2 per 5. jika garis tersebut melalui titik (2,3) dan (a,7)maka berapa nilai a ?

Answer 1

(y-3) / (7-3) = (x - 2) / (a-2)
(y-3)/4 = (x-2)/(a-2)
(a-2) y - 3 (a-2) = 4x -8
(a-2) y - 3a +2 = 4x -8
(a-2) y = 4x -10 + 3a
   y = 4/(a-2) x - (10 -3a)/(a-2)
   gradien = 2/5
2/5 = 4/ (a-2)
2 (a-2) = 20
 a-2 = 10
a = 12