Question

Explain how to write an equation of a line in standard form when two points on the line are given.

Answer 1

The general equation describing a line is y = m*x + b
if you have got two points, solve first for one of the variables m or b and the for the other

Answer 2

Example: you have the points (2, 4) and (3, 8), then you plug any in the equation, say (2, 4), and you get:
4 = m*2 + b, so b = 4 - 2m

now you do the other:

8 = m*3 + b, and you know b, so:
8 = 3m + (4 - 2m) = 4 - m, therefore m = -4

nnow you put that in the b equation and get:

b = 4 - 2m = 4 - 2*-4 = 12

So our line is y = -4x + 12 :)