Answer:
(a)-5°C
(b)21°C
Explanation:
• The temperature (in degrees Celsius) = y.
,
• The height (in kilometers) above the surface = x
The equation connecting x and y is given as:
![y=-5x+21](https://img.qammunity.org/2023/formulas/mathematics/college/xm7o2dveazi74t79o7y30nu3amy3ifzgjv.png)
(a)Compare the equation y=-5x+21 with the slope-intercept form:
![\begin{gathered} y=-5x+21 \\ y=mx+b \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/o7zo15594j7w6q0e7tifzfn7l21ijm90f7.png)
The slope, rate of change is -5.
Therefore, the temperature change for each kilometer we go up is -5°C.
(b)Temperature n the surface of the planet
On the surface of the planet, the height (above the surface), x = 0
![At\;x=0,y=21](https://img.qammunity.org/2023/formulas/mathematics/college/rbjjo3k351zdvn57n48v1q0m4fzkokfz2t.png)
Therefore, the temperature on the surface of the planet is 21°C.