Q:

Delores was given the points (0, 2) and (3, 5) and asked to find an equation that goes through those two points. Which is NOT a viable equation?

Accepted Solution

A:
The equations could possibly be:
y - 2 = 1(x - 0);
y - 2 = 1x
y = 1x + 2
y - 5 = 1(x - 3)
y - 5 = x - 3

We first find the slope of the line between the two points.  The formula for slope is
m = (y₂-y₁)/(x₂-x₁) = (5-2)/(3-0) = 3/3 = 1

Point-slope form of an equation is
y - y₁ = m(x - x₁)

Using our slope and the first point, we have 
y - 2 = 1(x - 0)

We can simplify this using the distributive property, and can then cancel the 2 by adding.

Using the second point and our slope the equation would be
y - 5 = 1(x - 3)

We can then simplify using the distributive property.