Doctors that take care of drawing blood

Solve this system of equations using the elimination method?

How can firms use marginal analysis to determine the price of a product? a) profit maximization can occur when the marginal cost exceeds the marginal revenue. b) the total cost of production can determine the individual unit price of a product. c) marginal analysis can be used to determine at what price profit maximization occurs. d) firms can calculate the marginal cost of a product and set the price lower than the cost.

When the blood leaves the atria (upper chambers) where does it flow to? a. aorta b. lungs c. ventricles d. rest of the body