Olga drew the regular figure shown here. She painted part of the figure a light color and part of it a darker color. She left the rest of the figure white. Which of the following equations best models the part of the figure Olga left white?

To answer this question, notice that this figure is a regular hexagon, having 6 equal sides and angles. The part painted darker can be represented by $1335_w19_h37.png$. The part painted lighter is clearly $7751_w9_h37.png$, which is equivalent to $5778_w9_h37.png$. The whole figure is represented by the number 1. So, 1 minus $1335_w19_h37.png$ minus $5778_w9_h37.png$ equals which is equivalent to $3366_w9_h37.png$. Therefore, the equation, $3525_w128_h37.png$ best models the part of the figure Olga left white.