If an order is for 500mg from a dosage strength of 250 mg/mL, is to be administered in 20 cc D5 1/2NS, how many mL of drug is used and how many mL of D5 1/2NS is used?

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

idk

step-by-step explanation:

the answer is y = 11.54

hope this : )