Answer:
C
Step-by-step explanation:
The elevati0on of sea level is 0 km and the elevation of the summit is 10 km
We are given:

Our goal in solving for any variable, in this case is x, we need to isolate x on one side of the variable. Let's start by subtracting 7x from both sides, which will cancel the +7x on the right side. We are then left with:

Now, we want to move that +10 to the other side so our x is all by itself. Let's subtract 10 from both sides, which will cancel the +10 on the right leaving us with:

Since we cannot have a coefficient when solving for x, we need to divide both sides by -3.

When we divide, our answer is:

Answer:
-1/2
if it's not right let me know
Step-by-step explanation:
Answer:
1 kilometer for every 10 minutes.
Step-by-step explanation:
Divide 30/3 to get your ratio