Need these answers correct asap

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.)

Part a : solve -vp + 40 < 65 for v part b : solve 7w - 3r = 15 for r show your work .

Glenda makes an online purchase for picture frames for $12.95 each and formats of $5.89 each the site says it taxes paid by the customer or 6.5% of the total purchase price shipping charges are based on the