A radioactive substance has a half-life of one week. In other words, at the end of every week the level of radioactivity is half of its value at the beginning of the week. The initial level of radioactivity is 20 counts per second.

a) The function that models the radioactivity remaining at the end of each week is

Labc is reflected across x = 1 and y = -3. what are the coordinates of the reflection image of a after both reflections?

Identify the number as a rational or irrational. explain. 127

Afarmer has a large field that is x feet in length. he wants to fence in a rectangular section in the middle of the field , leaving a length of 100 feet of open field behind each end of the fenced rectangle. he also wants the width of the fenced-in space to be 100 feet less than its length. find the expressions to represent the length and width of the fenced section of the field