All changes saved The half-life of a certain radioactive substance is 14 days. There are 6.6 grams of the substance
present initially. Which equation represents the number of grams of the radioactive substance
on day 42?
a: y= 6.6 - (0.5)28
b: y= 6.6 - (0.5)42
c: y= 6.6 - (0.5)
d: y = 6.6 - (0.5)14

The maximum distance (in nautical miles) that a radio transmitter signal can be sent is represented by the expression 1.23h√, where h is the height (in feet) above the transmitter. estimate the maximum distance x (in nautical miles) between the plane that is receiving the signal and the transmitter. round your answer to the nearest tenth.