Solve $u^{\text{'}}(t)u(t)=3$ subject to $u(2)=-5.$

$a^b,\frac{a}{b},\sqrt[\phantom{2}]{a},|a|,,sin(a)$A $150$ mg per L solution of drug is adminsitered intravenously at a rate of $50$ mL per hr to a patient with constant blood volume equal to $4$ L $.$ The drug is metabolized by the patient at an unknown rate such that $20\%$ of the drug is metabolized each hour.

Assuming the patient had no drug in their system before receiving treatment, how much is found in their system after $75$ minutes?

Answer: $8\mathrm{.}2950$ mg $($accuracy to at least four decimal places is required so do not round carelessly$).$ Please help with tgese questions