Fractions, Help!

Why do you multiply 75 over 2 by 4 over 43 to divide 37 and 1 over 2 by 10 and 3 over 4?

(Why do you multiply 75/2 by 4/43 to divide 37 1/2 by 10 3/4?)

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

What is the value of x in this triangle? a. 53° b. 62° c. 65° d. 118°

Divide reduce the answer to lowest term 3/7 divided 1 1/6