SOLUTION: Techology. Driving down a mountain, Tom finds that he has descended 1800 ft in elevation by the time he is 3.25 mi horizontally away from the top of the mountain. Find the slope of

Algebra ->  Linear-equations -> SOLUTION: Techology. Driving down a mountain, Tom finds that he has descended 1800 ft in elevation by the time he is 3.25 mi horizontally away from the top of the mountain. Find the slope of      Log On


   

Question 86561: Techology. Driving down a mountain, Tom finds that he has descended 1800 ft in elevation by the time he is 3.25 mi horizontally away from the top of the mountain. Find the slope of his descent to the nearest hundredth.

this is what I come up with
y=mx+b
y=3.25x+1800
Am I on the right track. I just don't know how to continue...
Found 2 solutions by checkley75, jim_thompson5910:
Answer by checkley75(3666) About Me  (Show Source):
You can put this solution on YOUR website!
YOU HAVE 2 POINTS TO GRAPH. ON THE Y AXIS (0,1800) & ON THE X AXIS (5,280*3.25,0).
NOW JUST FIND THE SLOPE (Y2-Y1)/(X2-X1)
(0-1800)/(5,280*3.25)
-1800/17,160
-.11 IS THE VALUE OF THE SLOPE.

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
First convert 3.25 mi into feet
3.25%2A%285280_feet%2F1_mile%29=17160_feet
Lets draw a picture to see whats going on:


Remember, the slope is the "rise" (which is the height) over the "run" (which is the base)
So the slope is

Slope=rise%2Frun=height%2Fbase=-1800%2F17160 note: since we are descending the rise is negative

Now reduce the fraction -1800%2F17160 to -15%2F143

So the slope is

-15%2F143

Now if you want it in decimal form, simply divide 15 by 143 like this

-15%2F143=-0.1048951048951

which to the nearest hundredth is

-.10