What’s 15+15-10 for math quiz help before I fail pls pls help someone

Write the point-slope form of the line passing through (2, -12) and parallel to y=3x.

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

Im so bad at fractions they are not my best math thing to work on