Question

What is the equation of the line that passes through the points (1, 2) and (-2, -13)?

Answer 1

Answer:

y = 5x - 3

Step-by-step explanation:

As we move from the point  (-2, -13) to the point (1, 2), we see the x-value (the 'run') increasing by 3 and the y-value (the 'rise') increasing by 15.  Therefore the slope of the line passing thru these two points is m = rise / run = 15/3, or m = 5.

Using the slope-intercept formyula y = mx + b, we find the y-intercept as follows, using 1 for x, 2 for y and 5 for m:

2 = 5(1) + b, or

b = -3

Then the desired equation is

y = 5x - 3