A double-blind experiment was conducted to evaluate the success of a Zika virus vaccine. What is the purpose of keeping treating physicians unaware of the treatment status of the experimental subjects?

To eliminate grounds for malpractice suits
To ensure subjects were assigned randomly to treatments
To remove a possible source of bias
To make sure nobody is injured
To avoid the placebo effect

To remove a possible source of bias

Step-by-step explanation:

If the test subjects know they are part of an experiement, this could cause them to think that it worked and it could either lead to untruthful answers or the test subjects tricking themselves to think that the vaccine worked

it's d.

step-by-step explanation:

because: -1(4x + 1y) +2 (1x-3y) distribute each number into the parenthesis.

then you would get: -4x - 1y + 2x -6y combine like terms

and get: 2x -7y

hope my answer has you if not then i'm sorry.

f is the midpoint of