The length of a rectangular mailing label is 5 centimeters less than twice the width

Which is true regarding the graphed function f(x)?

Which of the following represents a valid reason for statement #2

Use the domain {½ , 1, 2, 4, 8} to plot the points on the graph for the given equation. the grid marks represent one unit, the horizontal red line represents the x-axis, and the vertical red line represents the y-axis. y = log_2 x