Calculate the average cost per unit, using a perpetual inventory system. Assume a sale of 420 units occurred on June 15 for a selling price of $7 and a sale of 50 units on June 27 for $8.

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

c

step-by-step explanation:

need more detail

step-by-step explanation:

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