Letting x be the number of dvds, you could use the equation 8x + 12 = 84 to solve it, which would give you x = 9
Mult. the 2nd eqn by 6 and then add this "new" equation to the 1st given eqn:
-6x + y = -2
6x -18y = 54
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-17y = 52, or y = -52/17. Subst. this value of y into either equation to find the value of x.
Answer: The ans is imaginary . option c