My last math question! Plz help if you can and it asks for the elimination method. thank you!

Initially 100 milligrams of a radioactive substance was present. after 6 hours the mass had decreased by 4%. if the rate of decay is proportional to the amount of the substance present at time t, find the amount remaining after 24 hours. (round your answer to one decimal place.)

What two criteria are needed for triangles to be similar

Which of the following are accepted without proof in a logical system? check all that apply.