Which equation combines with the given equation to form a system of equations with the solution x = 3 and y = 9?

a. x + 2y = 21

b.4x + 6y = 64

c.2x + y = 36

d.4x + y = 21

e.-3x + 4y = 33

f.3x + 2y = 28

Create a graph for the demand for starfish using the following data table: quantity/price of starfish quantity (x axis) of starfish in dozens price (y axis) of starfish per dozen 0 8 2 6 3 5 5 2 7 1 9 0 is the relationship between the price of starfish and the quantity demanded inverse or direct? why? how many dozens of starfish are demanded at a price of five? calculate the slope of the line between the prices of 6 (quantity of 2) and 1 (quantity of 7) per dozen. describe the line when there is a direct relationship between price and quantity.