18. The population of a particular country was 18 million in 2005. In 2012, it was 22 million. The exponential growth function A = 18ell describes the population of this country t years after 2005. Find k for this model.

Which statements are true? check all that apply. the line x = 0 is perpendicular to the line y = –3. all lines that are parallel to the y-axis are vertical lines. all lines that are perpendicular to the x-axis have a slope of 0. the equation of the line parallel to the x-axis that passes through the point (2, –6) is x = 2. the equation of the line perpendicular to the y-axis that passes through the point (–5, 1) is y = 1.