Atoxic radioactive substance with a density of 9 milligrams per square centimeter is detected in the ventilating ducts of a nuclear processing building that was used 45 years ago if the half life of the substance is 20 years what was the density of the substance when it was deposited 45 years ago

Hurry and answer this! circle x with a radius of 6 units and circle y with a radius of 2 units are shown which steps would prove the circles similar? translate the circles so they share a common center point, and dilate circle y by a scale factor of 4. translate the circles so the center of one circle rests on the edge of the other circle, and dilate circle y by a scale factor of 4. translate the circles so they share a common center point, and dilate circle y by a scale factor of 3. translate the circles so the center of one circle rests on the edge of the other circle, and dilate circle y by a scale factor of 3

In dire need~! describe how to use area models to find the quotient 2/3 divided by 1/5. check your work by also finding the quotient 2/3 divided by 1/5 using numerical operations only.

Ahealth-food producer has 250 samples of a new snack to distribute in the mall. the producer has to keep at least 50 samples for display in the health food for the product launch. how long will the samples last if consumers are taking the samples at a rate of 25 every hour