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3 Points on a Line

A line segment containing the points (4,6) and (8,10) will also contain which of the following points?


Answer
Points that lie on the same line fit a line equation.  Let us first determine the line equation for the 2 given points

Determine slope (m) of the line that contains (4,6) and (8,10)

m  =  y2 - y1
  x2 - x1

m  =  10 - 6
  8 - 4

m  =  4
  4

m = 1

Step 2: Determine the line equation that has a slope of containing the point (x1, y1) = (4,6)

We know that the standard line equation is y = mx + b. Rearranging that equation to solve for b, we get b = y - mx. Using the point that you entered =(4,6) and the slope (m) = 1 that you entered, let's plug in those values and evaluate:
b = 6 - (1 * 4)
b = 6 - 4
b = 2

Step 3: Form line equation

Therefore, the line equation that contains the points (4,6) and (8,10) is y = 1x + 2

Plug in points to determine answer

Plugging in (7,9) as a potential answer, we get:
y = 1(7) + 2
y = 7 + 2
y = 9