Which of the following systems of equations is an example of one where substitution is the best method? A.)5x+3y=15
-3x+6=12
B.)y=2/7y+11
3x-4y=-24
C.)4x-5y=20
-6x+2y=-42
D.)x=4
Y=11

Acar traveling at 65 mph leaves 25 foot skid mark what is the ratio of the speed to length of skid mark (feet) in the simplest form

The parabola x = y² - 9 opens: a.)up b.)down c.) right d.)left

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.)