Explanation:
get the gradient by dividing change of y with change of x
6 - 3/3 -2 =3/1=3
then equate the gradient to the equation by taking any two points say point (2,3)
Y - 3/X - 2 = 3
cross multiplication will give
Y - 3= 3X - 6.
collect like terms
Y = 3X - 6 +3
Y = 3X - 3