document.write( "Question 158574: Road Gradient Driving down the smoky mountains in Tenn. Sam finds that she decends 2000 feet in elevation during the time that she has moved 4 miles horizontally away from a high point on the straight road. Find the slope (gradient) of the road (1 mile+5280 feet)
\n" ); document.write( "Please help I am stumped on how the equation should be wriiten in order to have it solved! Thanks so much \n" ); document.write( "
Algebra.Com's Answer #116838 by gonzo(654)\"\" \"About 
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it looks like what they are looking for is a change in the vertical direction divided by the change in the horizontal direction.
\n" ); document.write( "if you let y = vertical direction and x = horizontal direction, then change in vertical direction divided by change in horizontal direction is the slope.
\n" ); document.write( "so change in vertical direction is given by the equation y2-y1 = change in vertical direction.
\n" ); document.write( "change in the horizontal direction is given by the equation x2-x1 = change in horizontal direction.
\n" ); document.write( "slope is y2-y1/x2-x1
\n" ); document.write( "y1 = 2000 (her starting elevation in feet
\n" ); document.write( "y2 = 0 (her finishing elevation
\n" ); document.write( "x1 = 0 (her starting horizontal miles
\n" ); document.write( "x2 = 4 (her finishing horizontal miles
\n" ); document.write( "formula then becomes
\n" ); document.write( "y2-y1 = 0 - 2000 = (-2000) feet
\n" ); document.write( "x2-x1 = 4 - 0 = 4 miles
\n" ); document.write( "(y2-y1)/(x2-x1) becomes
\n" ); document.write( "-2000/4 = -500 feet per mile.
\n" ); document.write( "if you were to graph this, you would use the slope intercept form of the general equation y = m*x + b, where m is the slope and b is the y intercept when x = 0.
\n" ); document.write( "x represents horizontal direction in miles
\n" ); document.write( "y represents elevation in feet
\n" ); document.write( "the slope is -500/feet per mile
\n" ); document.write( "when x is 0, y is 2000 (given) so b is 2000 which is the y-intercept.
\n" ); document.write( "formula then becomes
\n" ); document.write( "y - -500*x+2000
\n" ); document.write( "the graph of this equation would look like this:
\n" ); document.write( "\"graph%28600%2C600%2C-4%2C4%2C-2000%2C2000%2C-500x%2B2000%29\"
\n" ); document.write( "as you can see, when x = 0 miles, elevation is 2000 feet, and when x = 4 miles, elevation is 0 feet. \n" ); document.write( "
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