Answer:
None of the expressions are equivalent, but there may be a typo. I that is the case, the first answer is most likely correct(it should be 3x²+x-4).
Step-by-step explanation:
Answer:23.3/100 or 23.3%
Step-by-step explanation:
Answer:
40% of the boys ate grapes :)
Thank you
Let Q(t) = the mass (mg) remaining after t hours.
We are told that Q diminishes by 3% every hour.
When t = 0, Q = 4 mg
When t = 1, Q = 4*0.97 mg
When t = 2, Q = 4*(0.97)² mg
By induction,

Q'(t) = 0.97Q
Therefore the rate of decrease is 3% per hour.
The person receives an additional dosage when Q falls to 0.50 mg. This happens when

After the second injection, the mass is now 4.5 mg. Therefore

When the mass again reaches 0.50 mg, then

Answers:
(a)

(b) 3% per hour
(c) 68.3 hours
(d) 72.1 hours