I am experimenting with the SymPy module, and I wrote the following code to estimate moments 1 and 2 given moments 3 and 4. With two equations and two unknowns I should get exact answers, but the following code returns “any”. Does anyone know why this happens?

```
m3 = mean(inv07.^3)
m4 = mean(inv07.^4)
using SymPy
# define the symbols for the unknowns
x, y = symbols("x y")
# define the equations
eq1 = 3*x^2*y + y^3 - m3
eq2 = 3x^4 + 6*x^2*y^2 +y^4 - m4
# solve the system of equations
soln = solve([eq1, eq2], [x, y])
println(soln)
```