The answer is 9 I believe
Answer:
striped
Step-by-step explanation:
Answer:
The substance half-life is of 4.98 days.
Step-by-step explanation:
Equation for an amount of a decaying substance:
The equation for the amount of a substance that decay exponentially has the following format:

In which k is the decay rate, as a decimal.
k-value of 0.1392.
This means that:

Find the substance's half life, in days.
This is t for which
. So







The substance half-life is of 4.98 days.
Multiply the price by (1 + sales tax).
85 x (1+0.07)
85 x 1.07 = 90.95
He will pay $90.95
Answer:
f=10
Step-by-step explanation:
I don't know a formula for this but I can see that <CRE is a 90° angle so 7f+2f=90 and if f=10 7f=70 and 2f=20 which fits