ANSWERS ASAP!! Howdy everyone! I need help with these 3 math problems by just filling the numbers 4-19 Please don't answer random dumb questions for the points, be kind and actually help me!

What is the value of x divided into y - z if x = 32, y = 4, and z = 2 3/4?

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 is the difference between the predicted value and the actual value