I’LL MARK BRAINLEST! :)

Inez has a phone card. the graph shows the number of minutes that remain on her phone card a certain number of days.

The weight of a radioactive isotope was 96 grams at the start of an experiment. after one hour, the weight of the isotope was half of its initial weight. after two hours, the weight of the isotope was half of its weight the previous hour. if this pattern continues, which of the following graphs represents the weight of the radioactive isotope over time? a. graph w b. graph x c. graph y d. graph z

Asap! will mark brainliest! ( respond asap, it's urgent! : )) what is the slope for equation y =-3x + 8