Question 185353
It is 76 degrees F at the 6000-foot level of a mountain, and 49 degrees
 F at the 12000-foot level of a mountain. 
Write a linear equation to find the temperature T at an elevation e on the
 mountain, where e is in thousands of feet.:
:
Find the slope using the slope formula: m = {{{(y2-y1)/(x2-x1)}}}
Assign the given values as follows
x1 = 6 (for 6000 ft);  y1 = 76
x2 = 12(for 12000ft);  y2 = 49
:
m = {{{(49-76)/(12-6)}}} = {{{(-27)/6}}} = {{{-9/2}}}
;
Use the point slope equation y - y1 = m(x - x1) so create the equation
y - 76 = {{{-9/2}}}(x - 6)
y - 76 = {{{-9/2}}}x - (-27)
y - 76 = {{{-9/2}}}x + 27 + 76
y = {{{-9/2}}}x + 103; is the equation
Using e and T
T = {{{-9/2}}}e + 103
:
A graph would look like this:
{{{ graph( 300, 200, -10, 20, -20, 120, (-9/2)x+103) }}}
where elevation is the horizontal and Temp is the vertical
;
Sorry for the initial screw-up here. Carl