System of equations in python symbolically

I want to solve this system symbolically but it didn’t work. where did I make the mistake? and how can I solve it?

import numpy as np
from sympy import symbols,Matrix
Y, C, I0, G0, a, b = symbols('Y, C, I_0, G_0, a, b')
npA = np.array(([1, -1], [-b, 1]))
npd = np.array((I0 + G0, a))
x = np.linalg.solve(npA, npd)
x

I get this error

---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
<ipython-input-42-7ec4f3174f18> in <module>
      5 npA = np.array(([1, -1], [-b, 1]))
      6 npd = np.array((I0 + G0, a))
----> 7 x = np.linalg.solve(npA, npd)
      8 x

<__array_function__ internals> in solve(*args, **kwargs)

~anaconda3libsite-packagesnumpylinalglinalg.py in solve(a, b)
    392     signature = 'DD->D' if isComplexType(t) else 'dd->d'
    393     extobj = get_linalg_error_extobj(_raise_linalgerror_singular)
--> 394     r = gufunc(a, b, signature=signature, extobj=extobj)
    395 
    396     return wrap(r.astype(result_t, copy=False))

TypeError: No loop matching the specified signature and casting was found for ufunc solve1

Answer

You are attempting to solve such an equation: Ax = b. I don’t think you can mix-up command from different libraries like that, there is some compatibility but you should check the documentation

Here a possibility

from sympy import symbols, Eq, solve

a_x, a_y, b_x, b_y = symbols('a_x, a_y, b_x, b_y')

eq_x = Eq(a_x - a_y, b_x)
eq_y = Eq(-b_x * a_x + a_y, b_y)

result = solve([eq_x, eq_y],(b_x, b_y))

print(result[b_x])
print(result[b_y])

Output

a_x - a_y
-a_x**2 + a_x*a_y + a_y