The equation x' - 3x = 1 has a solution between 1.8 and 1.9 Use a trial and improvement method to find this solution. Give your answer correct to 2 decimal places. You must show all your working. On the same line as your final answer you must write "to 2 decimal places".

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