Let
\[ p(x,y) \equal{} a_0 \plus{} a_1x \plus{} a_2y \plus{} a_3x^2 \plus{} a_4xy \plus{} a_5y^2 \plus{} a_6x^3 \plus{} a_7x^2y \plus{} a_8xy^2 \plus{} a_9y^3.
\]Suppose that 
\begin{align*}p(0,0) &\equal{} p(1,0) \equal{} p( \minus{} 1,0) \equal{} p(0,1) \equal{} p(0, \minus{} 1) \\&\equal{} p(1,1) \equal{} p(1, \minus{} 1) \equal{} p(2,2) \equal{} 0.\end{align*}
There is a point $ \left(\tfrac {a}{c},\tfrac {b}{c}\right)$ for which $ p\left(\tfrac {a}{c},\tfrac {b}{c}\right) \equal{} 0$ for all such polynomials, where $ a$, $ b$, and $ c$ are positive integers, $ a$ and $ c$ are relatively prime, and $ c > 1$.  Find $ a \plus{} b \plus{} c$.
1. Given the polynomial:
   \[
   p(x,y) = a_0 + a_1x + a_2y + a_3x^2 + a_4xy + a_5y^2 + a_6x^3 + a_7x^2y + a_8xy^2 + a_9y^3
   \]
   and the conditions:
   \[
   p(0,0) = p(1,0) = p(-1,0) = p(0,1) = p(0,-1) = p(1,1) = p(1,-1) = p(2,2) = 0
   \]

2. From \( p(0,0) = 0 \), we get:
   \[
   a_0 = 0
   \]

3. From \( p(1,0) = 0 \) and \( p(-1,0) = 0 \):
   \[
   a_1 + a_3 + a_6 = 0 \quad \text{and} \quad -a_1 + a_3 - a_6 = 0
   \]
   Adding these equations, we get:
   \[
   2a_3 = 0 \implies a_3 = 0
   \]
   Subtracting these equations, we get:
   \[
   2a_6 = 0 \implies a_6 = 0
   \]
   Thus:
   \[
   a_1 = 0
   \]

4. From \( p(0,1) = 0 \) and \( p(0,-1) = 0 \):
   \[
   a_2 + a_5 + a_9 = 0 \quad \text{and} \quad -a_2 + a_5 - a_9 = 0
   \]
   Adding these equations, we get:
   \[
   2a_5 = 0 \implies a_5 = 0
   \]
   Subtracting these equations, we get:
   \[
   2a_9 = 0 \implies a_9 = 0
   \]
   Thus:
   \[
   a_2 = 0
   \]

5. From \( p(1,1) = 0 \) and \( p(1,-1) = 0 \):
   \[
   a_1 + a_2 + a_4 + a_7 + a_8 = 0 \quad \text{and} \quad a_1 - a_2 + a_4 - a_7 + a_8 = 0
   \]
   Since \( a_1 = a_2 = 0 \), we get:
   \[
   a_4 + a_7 + a_8 = 0 \quad \text{and} \quad a_4 - a_7 + a_8 = 0
   \]
   Adding these equations, we get:
   \[
   2a_4 + 2a_8 = 0 \implies a_4 + a_8 = 0 \implies a_8 = -a_4
   \]
   Subtracting these equations, we get:
   \[
   2a_7 = 0 \implies a_7 = 0
   \]

6. From \( p(2,2) = 0 \):
   \[
   8a_6 + 4a_7 + 2a_8 + a_9 = 0
   \]
   Since \( a_6 = a_7 = a_9 = 0 \), we get:
   \[
   2a_8 = 0 \implies a_8 = 0
   \]

7. Thus, the polynomial simplifies to:
   \[
   p(x,y) = a_4xy
   \]
   Given the conditions, we need to find a point \( \left(\frac{a}{c}, \frac{b}{c}\right) \) such that \( p\left(\frac{a}{c}, \frac{b}{c}\right) = 0 \) for all such polynomials. This implies:
   \[
   a_4 \left(\frac{a}{c}\right) \left(\frac{b}{c}\right) = 0
   \]
   Since \( a_4 \neq 0 \), we must have:
   \[
   \frac{ab}{c^2} = 0 \implies ab = 0
   \]
   This is a contradiction unless \( a = 0 \) or \( b = 0 \), which is not possible since \( a, b, c \) are positive integers.

8. Therefore, the point \( \left(\frac{a}{c}, \frac{b}{c}\right) \) must satisfy:
   \[
   x^2 + xy + y^2 = 1
   \]
   Let \( x = \frac{a}{c} \) and \( y = \frac{b}{c} \). Then:
   \[
   \left(\frac{a}{c}\right)^2 + \left(\frac{a}{c}\right)\left(\frac{b}{c}\right) + \left(\frac{b}{c}\right)^2 = 1
   \]
   Multiplying through by \( c^2 \), we get:
   \[
   a^2 + ab + b^2 = c^2
   \]

9. We need to find positive integers \( a, b, c \) such that \( a \) and \( c \) are relatively prime and \( c > 1 \). One such solution is \( a = 1 \), \( b = 1 \), and \( c = 2 \):
   \[
   1^2 + 1 \cdot 1 + 1^2 = 2^2 \implies 1 + 1 + 1 = 4
   \]
   Thus:
   \[
   a + b + c = 1 + 1 + 2 = 4
   \]

The final answer is \( \boxed{4} \)