First let’s find the slope (gradient):
We pick 2 coordinates on the line. Let’s choose (2,100) and (8,400)
Gradient = (y2-y1)/(x2-x1) = (400-100)/(8-2) = 300/6 = 50
The general equation of a line is in the form y = mx + c, where m is the gradient
So we have, y = 50x + c
To find c, we replace one of the coordinates that we chose in the equation. Let’s replace (2,100)
100 = 50(2) + c
100 = 100 + c
c = 100 - 100 = 0
Therefore, the equation is y = 50x + 0 which is y = 50x
