Robert, Brenna, and Christian got different answers for this problem: (-40)-2[(-8)÷2] Robert's answer was -32, Christian's answer was -48, and Brenna's is 168. Which student had the correct answer?
Explain how the other two got their answers. What errors did they make?

Factor this polynomial completely x^2-64

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.)

The graph of a hyperbola is shown. what are the coordinates of a vertex of the hyperbola? (0, −4) (−3, 0) (0, 0) (0, 5)