Implicit Differentiation. The demand equation for a certain brand of two-way headphones is 4x3 +5xy + 4y2 = 18 where x represents the number (in thousands) of headphones demanded each week when the unit price is y. Find y by implicit differentiation for the given equation. dx O dy _ 12x2+5y dx +5x + 8y dy - -(12x2+ 5y) dx +5x + 8y dy -12x2 dx +5x + 8y O none of the other answers O dy - -12x2 dx +5 + 8y