Which set of ordered pairs represents y as a function of x?

How do newtons third law of motion demonstrates on a rollar coster

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.

Multiply and simplify 2x^2 y^3 z^2 · 4xy^4 x^2