Write an inequality that includes (0,9), (-10, 10), (10, -20), and (-20, 15) as solutions.

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.)

Write two subtraction equations that are equivalent to 5 + 12 = 17.

What is the lcm of 16 and 40 ? 24 and 40 ?