-4x+29? I think that's what you're asking.
Since x is our unknown number, on one side of our equation we will have the "<span>Subtracting two times a number from 10", and on the other will be -3. So,
-3=10-2x</span>
The formula for the lateral surface area of a right circular cone is:

where r is the radius of the base, and l is the slant height.
Plugging in the values we get:
Answer:
a) There will be approximately a water depth of 7.5 meters after 3h
b) Approximately 2.5 hours have passed when there is 8 m of water in the tank.
Step-by-step explanation:
a) Look for the y-value when the x-value is 3.
b) Look for the x-value when the y-value is 8.
*The y-axis is the depth (m), and the x-axis is the time (h).