How can i do the work and explain this?

When using the linear combination metho e linear combination method to solve a system of linear equations, the four options are:

Which value would be a solution for x in the inequality 47-4x< 7

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