A patient recieves 3 times the amount of certain medicines as patient B. The two doses add to 200 milligrams. What amount of the medicine does each patient receive?

if A = 3x and B = x

your equation will look like: 3x + x = 200

combine like terms to get 4x = 200

then, divide each side by 4 to get x = 50

if x = 50, then patient B receives 50 mg. to find A, you can either subtract 50 from 200 or you can take 50 multiplied by 3. patient A receives 150 mg.