A radioactive sample was created in 1980. In 2002, a technician measures the radioactivity at 42.0 rads. One year later, the radioactivity is 39.8 rads. a. Find the ratio of radioactivity between 2002 and 2003. Approximate your answer to four decimal places.
b. Let x represent the year, and let y represent the radioactivity in rads. Write an equation in point-ratio form, y = y1 bx-x1, using the point (x1, y1) = (2002, 42).
c. Write an equation in point-ratio form using the point (2003, 39.8).
d. Calculate the radioactivity in 1980 using both equations.
e. Calculate the radioactivity in 2010 using both equations.
f. Use the properties of exponents to show that the equations in 14b and c are equivalent?