9/2 divided by 2/9 this is dividing fractions

Agiven line has the equation 2x + 12y = −1. what is the equation, in slope-intercept form, of the line that is perpendicular to the given line and passes through the point (0, 9)? y = ( )x + 9

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.)

How do i make someone brainliest? (if you answer me, i might be able to make you brainliest! )