Help me solve this plz 7(3x+6)=11-(x+2)

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.)

Ben is three times as old as samantha, who is two years older than half of michel's age. if michel is 12. how old is ben?

If the measure of angle 1 is 110 degrees and the measure of angle 3 is (2 x+10 degree), what is the value of x?