1. **State the problem:**
Find the derivative $\frac{dy}{dx}$ implicitly from the equation $6x - 5y^2 - 3xy - x = 11$ and evaluate it at the point $(1,3)$.
2. **Rewrite the equation:**
$$6x - 5y^2 - 3xy - x = 11$$
Simplify the left side:
$$6x - x - 5y^2 - 3xy = 11$$
$$5x - 5y^2 - 3xy = 11$$
3. **Differentiate both sides with respect to $x$ implicitly:**
Use the product rule for $-3xy$ and chain rule for $y^2$:
$$\frac{d}{dx}(5x) - \frac{d}{dx}(5y^2) - \frac{d}{dx}(3xy) = \frac{d}{dx}(11)$$
4. **Calculate each derivative:**
$$5 - 5 \cdot 2y \frac{dy}{dx} - \left(3y + 3x \frac{dy}{dx}\right) = 0$$
5. **Simplify:**
$$5 - 10y \frac{dy}{dx} - 3y - 3x \frac{dy}{dx} = 0$$
6. **Group terms with $\frac{dy}{dx}$ and constants:**
$$5 - 3y = 10y \frac{dy}{dx} + 3x \frac{dy}{dx}$$
7. **Factor out $\frac{dy}{dx}$:**
$$5 - 3y = \left(10y + 3x\right) \frac{dy}{dx}$$
8. **Solve for $\frac{dy}{dx}$:**
$$\frac{dy}{dx} = \frac{5 - 3y}{10y + 3x}$$
9. **Evaluate at the point $(1,3)$:**
$$\frac{dy}{dx} = \frac{5 - 3 \times 3}{10 \times 3 + 3 \times 1} = \frac{5 - 9}{30 + 3} = \frac{-4}{33}$$
**Final answer:**
$$\boxed{\frac{dy}{dx} = -\frac{4}{33}}$$
Implicit Derivative F04958
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