Conan had 180$ in the bank. each week he deposits another 64$ that he earns mowing lawns. is his account balance proportional to the number of weeks since he started mowing the lawn

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