Answer:

Step-by-step explanation:
Given the exponential decay function 
When
then

so the initial amount is 
The exponential decay function
has the decay factor 
In your case, the eexponential decay factor is 
Answer:
5
Step-by-step explanation:
As corresponding lines are equal
16x+1 = 79
16x = 80
x = 5
well, we know that θ is in the III Quadrant, where the sine is negative and the cosine is negative as well, or if you wish, where "x" as well as "y" are both negative, now, the hypotenuse or radius of the circle is just a distance amount, so is never negative, so in the equation of cos(θ) = - (2/5), the negative must be the adjacent side, thus

