What's the opposite of the opposite of 2?

Sole with work in 10 years, the average number of hours of tv watched per week by teenagers dropped from 23.9 to 21.4. find the percent of change.

Which of the following describes the graph of y--4x-36 compared to the parent square root function? stretched by a factor of 2, reflected over the x-axis, and translated 9 units right stretched by a factor of 2, reflected over the x-axis, and translated 9 units left stretched by a factor of 2, reflected over the y-axis, and translated 9 units right stretched by a factor of 2, reflected over the y-axis, and translated 9 units left save and exit next submit

Suppose a laboratory has a 30 g sample of polonium-210. the half-life of polonium-210 is about 138 days how many half-lives of polonium-210 occur in 1104 days? how much polonium is in the sample 1104 days later? 9; 0.06 g 8; 0.12 g 8; 2,070 g