Answer:

Step-by-step explanation:
- Simplify




- Find the additive inverse of
by using its property - <em>"Sum of a number & its additive inverse is always zero". </em>Assume that 'x' is an additive inverse of
.


- Simplify




- Now, find the product of
& 


Given:
Initial mass, m₀ = 23 g
Decay constant, k = 0.13
Exponential decay obeys the equation

where t = time, days
For half life, the mass is m = m₀/2.
Therefore

Answer: The half life is 5.33 days
Answer:
Vertical distance between the valley and the summit = 8062.5 ft
Step-by-step explanation:
Distances above the sea level are denoted by positive notations and below the sea level by negative notation.
Summit of a mountain pass = 8050 (above the sea level)
Valley below the sea level = 12 and half ft = (-12.5) ft
Distance between the summit and the valley = 8050 - (-12.5)
= 8050 + 12.5
= 8062.5 ft
Therefore, Vertical distance = 8062.5 ft will be the answer.