Let $x_1$, $x_2$, and $x_3$ be the roots of the polynomial $x^3+3x+1$.  There are relatively prime positive integers $m$ and $n$ such that $\tfrac{m}{n}=\tfrac{x_1^2}{(5x_2+1)(5x_3+1)}+\tfrac{x_2^2}{(5x_1+1)(5x_3+1)}+\tfrac{x_3^2}{(5x_1+1)(5x_2+1)}$.  Find $m+n$.
1. Let the roots of the polynomial \(x^3 + 3x + 1\) be \(\alpha, \beta, \gamma\). By Vieta's formulas, we have:
   \[
   \alpha + \beta + \gamma = 0,
   \]
   \[
   \alpha\beta + \beta\gamma + \gamma\alpha = 3,
   \]
   \[
   \alpha\beta\gamma = -1.
   \]

2. We need to find the value of \(\frac{m}{n}\) where \(m\) and \(n\) are relatively prime positive integers such that:
   \[
   \frac{\alpha^2}{(5\beta+1)(5\gamma+1)} + \frac{\beta^2}{(5\alpha+1)(5\gamma+1)} + \frac{\gamma^2}{(5\alpha+1)(5\beta+1)} = \frac{m}{n}.
   \]

3. First, we calculate the product \((5\alpha+1)(5\beta+1)(5\gamma+1)\):
   \[
   (5\alpha+1)(5\beta+1)(5\gamma+1) = 5^3 \alpha \beta \gamma + 5^2 (\alpha \beta + \beta \gamma + \gamma \alpha) + 5 (\alpha + \beta + \gamma) + 1.
   \]
   Substituting the values from Vieta's formulas:
   \[
   = 5^3 (-1) + 5^2 (3) + 5 (0) + 1 = -125 + 75 + 0 + 1 = -49.
   \]

4. Therefore, we have:
   \[
   (5\beta+1)(5\gamma+1) = \frac{-49}{5\alpha+1},
   \]
   \[
   (5\alpha+1)(5\gamma+1) = \frac{-49}{5\beta+1},
   \]
   \[
   (5\alpha+1)(5\beta+1) = \frac{-49}{5\gamma+1}.
   \]

5. Now, we substitute these into the original expression:
   \[
   \frac{\alpha^2}{(5\beta+1)(5\gamma+1)} + \frac{\beta^2}{(5\alpha+1)(5\gamma+1)} + \frac{\gamma^2}{(5\alpha+1)(5\beta+1)} = \frac{\alpha^2}{\frac{-49}{5\alpha+1}} + \frac{\beta^2}{\frac{-49}{5\beta+1}} + \frac{\gamma^2}{\frac{-49}{5\gamma+1}}.
   \]
   Simplifying, we get:
   \[
   = -\frac{\alpha^2 (5\alpha+1)}{49} - \frac{\beta^2 (5\beta+1)}{49} - \frac{\gamma^2 (5\gamma+1)}{49}.
   \]

6. We need to find \(\alpha^3, \beta^3, \gamma^3\). Using the polynomial \(x^3 + 3x + 1 = 0\), we have:
   \[
   \alpha^3 = -3\alpha - 1,
   \]
   \[
   \beta^3 = -3\beta - 1,
   \]
   \[
   \gamma^3 = -3\gamma - 1.
   \]

7. Summing these, we get:
   \[
   \alpha^3 + \beta^3 + \gamma^3 = -3(\alpha + \beta + \gamma) - 3 = -3.
   \]

8. We also need \(\alpha^2 + \beta^2 + \gamma^2\). Using the identity:
   \[
   (\alpha + \beta + \gamma)^2 = \alpha^2 + \beta^2 + \gamma^2 + 2(\alpha\beta + \beta\gamma + \gamma\alpha),
   \]
   we get:
   \[
   0 = \alpha^2 + \beta^2 + \gamma^2 + 2 \cdot 3,
   \]
   \[
   \alpha^2 + \beta^2 + \gamma^2 = -6.
   \]

9. Substituting these into our expression, we get:
   \[
   -\frac{5(\alpha^3 + \beta^3 + \gamma^3) + (\alpha^2 + \beta^2 + \gamma^2)}{49} = -\frac{5(-3) + (-6)}{49} = -\frac{-15 - 6}{49} = \frac{21}{49} = \frac{3}{7}.
   \]

10. Therefore, \(m = 3\) and \(n = 7\), and \(m+n = 3+7 = 10\).

The final answer is \(\boxed{10}\).