Write 3x-y+9=0 in slope intercept form

can somebody explain to me how to get the solution

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.)

To prove that def ~ gfh by the sss similarity theorem using the information provided in the diagram, it would be enough additional information to know that

Which of the following answers is 5/25 simplified? 1/5 5/5 2/5 1/25