First let us find the slope between the two points.
Slope = Change in y / Change in x.
(3, 6) and (8, 4) compares to (x₁, y₁) and (x₂, y₂)
Slope = (y₂ - y₁) / (x₂ - x₁) = (4 - 6) / (8 - 3) = -2/5
Slope m = -2/5= -0.4
Using y = mx + c, using point (3, 6)
y = -0.4x + c
6 = -0.4*3 + c
6 = -1.2 + c
6 + 1.2 = c
7.2 = c
c = 7.2
Equation = : y = -0.4x +c
y = -0.4x + 7.2
y = -4/10 + 72/10
10y = -4x + 72
5y = -2x + 36
Equation =: 5y = -2x + 36
Hope this explains it.
