Does commutative property use multiplication and subtraction?

At store a, erasers are sold individually. the cost y of x erasers is represented by the equation y=0.75x. the costs of erasers at store b are shown in the graph.

Ethan is proving that the slope between any two points on a straight line is the same. he has already proved that triangles 1 and 2 are similar. drag statements and reasons to complete the proof.

Which expression represents the total perimeter of her sandwich, and if x = 1.2, what is the approximate length of the crust?