Idont understand this. a 25 gram sample substance that's used for drug research has a k-value of 0.1229. find the substances half-life, in days using the exponential decay formula. round your answer to the nearest tenth

Half life period = 43.11 days

Step-by-step explanation:

A sample substance has been taken for the use of drug research.

Weight of the substance taken = 0.25 gram

We have to use the formula of exponential decay to find the half life period of the substance.

Formula for the decay is

Where is the weight of the substance taken initially

is the quantity remained after t time

and t = time

Now we have to find the half life life period

=

and

By putting these values in the formula

0.125 = 25

=

= 0.005

Now we take natural log on both the sides of the equation

-0.1229t(lne) = -5.2983

0.1229t = 5.2983

t = ≈ 43.10 days

Therefore, half life period of the substance is 43.10 days

b

step-by-step explanation:

a difference is the result of subtraction. while each of these expressions has subtraction in it, a difference will be the result when subtraction is the last operation applied in the order of operations for the expression. this means subtraction must be outside of the parenthesis. only b has this.

step-by-step explanation:

bob the banana