If the domain and range have the same number is it still a function??

When can u say there is no solution for a system of linear inequalities? explain your answer and show with a system and graph

Adoctor administers a drug to a 38-kg patient, using a dosage formula of 50 mg/kg/day. assume that the drug is available in a 100 mg per 5 ml suspension or in 500 mg tablets. a. how many tablets should a 38-kg patient take every four hours? b. the suspension with a drop factor of 10 ggt/ml delivers the drug intravenously to the patient over a twelve-hour period. what flow rate should be used in units of ggt/hr? a. the patient should take nothing pills every four hours. (type an integer or decimal rounded to the nearest hundredth as needed.)

Iwill give ! if m∠a=59 and m∠3=81°, what is m∠b? m∠b= _[blank]_°