60 minutes. Take how far it is above ground (20 m) and add it to the absolute value of how far it is below ground (340 m) to get 360 meters, which you divide by the rate of descent (6 m/min) to get 60 minutes.
20 ft because the shadow would be 3/2 of the height. 9 is 3/2 of 6 so the height would be 20 bc 30 is 3/2 of 20
Simplify. Combine like terms
12x - 9x = 3x
7 - 15 = -8
3x - 8 is your answer
hope this helps
