In which set are all fractions equivalent to negative 2/3? { 2/−3, −2/−3, −9/12}

{ 2/−3 ,−2/3, −8/12}

{ 2/−3, −2/3, −9/12}

{2/−3 ,−2/−3, −8/12}

Aresearch company wants to test the claim that a new multivitamin to improve short term memory. state the objective of the experiment, suggest a population, determine the experimental and control groups, and describe a sample procedure.

Bring the fraction a/a-4 to a denominator of 16-a^2

Apinhole camera is made out of a light-tight box with a piece of film attached to one side and pinhole on the opposite side. the optimum diameter d(in millimeters) of the pinhole can be modeled by d=1.9[ (5.5 x 10^-4) l) ] ^1/2, where l is the length of the camera box (in millimeters). what is the optimum diameter for a pinhole camera if the camera box has a length of 10 centimeters