9.) a: The relationship between x and y is linear, as the line is straight and it passes through the orgin, and the values are proportional.
b: According to the graph, the drill team will have to pay $72 if they purchase 12 uniforms.(y=60x; 12=60(12))
10.) The relationship between x and y is nonlinear, as the line is not straight, nor pass through the orgin, which makes it also nonproportional.