Question

its 76 degrees fahrenheit at the 6000-foot level of a mountain, and 49 degrees Fahrenheit at the 12000-foot level of the mountain. write a liner equation to find the temperature T at an elevation x on the mountain, where x is in thousands of feet.

Answer 1

$T = \frac{-9}{2}x + 103$ is the linear equation to find the temperature T at an elevation x on the mountain, where x is in thousands of feet.

Solution:

The linear equation in slope intercept form is given as:

T = cx + k ------ (i)

Where "t" is the temperature at an elevation x

And x is in thousands of feet

Given that its 76 degrees fahrenheit at the 6000-foot level of a mountain

Given, when c = 6 thousand ft and $T = 76^{\circ}$ fahrenheit

This implies,

From (i)

76 = c(6) + k

76 = 6c + k

⇒ k = 76 - 6c  ----- (ii)

Given that 49 degrees Fahrenheit at the 12000-foot level of the mountain

Given, when c = 12 thousand ft and $T = 49^{\circ}$ fahrenheit

This implies,

From (i)

49 = c(12) + k

49 = 12c + k

Substitute (ii) in above equation

49 = 12c + (76 - 6c)

49 = 12c + 76 - 6c

49 - 76 = 6c

6c = -27

$c = \frac{-9}{2}$

Substituting the value of c in (ii) we get

$k = 76 - 6( \frac{-9}{2})\\\\k = 76 + 27 = 103$

Substituting the value of c and k in (i)

$T = \frac{-9}{2}x + 103$

Where "x" is in thousands of feet

Thus the required linear equation is found