the missing value will be -36 because if you multiplied it with 4 you will only have to add another -4 to get -144
Answer:
x = -5
Step-by-step explanation:
x - 15 = -20
+ 15 + 15
x = -5
Using an exponential function, it is found that 4 mg of the substance would still be left after 32 days.
<h3>What is an exponential function?</h3>
A decaying exponential function is modeled by:

In which:
- A(0) is the initial value.
- r is the decay rate, as a decimal.
In this problem, considering that the initial amount if of 64 mg, and we are working with half-lifes, the equation is given by:

32 days is 32/8 = 4 half-lifes, hence the amount remaining in mg is given by:

More can be learned about exponential functions at brainly.com/question/25537936
Answer:
800 km
Step-by-step explanation:
Does the plane have a speed of it's own? I don't see it, so will assume the plane is simply travelling at 300 km/h.
(300 km/hr)*(1 hr/60 min) = 5 km/min
(5 km/min)*(160 min) = 800 km in 160 minutes