Question

Find the point-slope equation for the line that passes through the points (30,2) and (15,-28) use the first point in your equation

Answer 1

Answer:

y=2x-58

Explanation:

In order to write our point-slope formula (y=mx+C format), we first need to figure out the slope (m). To figure out the slope, we divide the change in y by the change in x between the two points (rise/run). The rise is 30 (2-(-28)) and the run is 15 (30-15). Therefore the slope is 2 (30/15)

This gives us:

y=2x + c

Now to figure out C (which will be the y-intercept of the graph) we substitute in the values from one of the points. So our x=30 and our y=2:

2=2(30) + c

2=60+c

2-60=c

-58=c

So now we know that our C (constant) is - 58.

Hence our point-slope formula is:

y=2x-58

Which you can test with the other point:

-28=2(15) - 58

Hope this helped!