Python solve linear equation with substitution

I am trying to learn Python for a physics class, but I have tried to code the function of

E1 - i1R1 + i3R3 = 0;
-i3R3 - i2R2 - E2 = 0;
and E1 - i1R1 - i2R2 - E2 = 0.

And solve it by using a matrix. The variables are given to be E1 = 5V, E2 = 3V, R1 = 10 Ohms, R2 = 15 Ohms, and R3 = 5 Ohms.

Find i1, i2, and i3. Please help me. This is a homework question.

I use this code but it kept saying linalg error due to 1 dimension, it require 2.

import numpy as np
A = np.array([[5,10,5],[-5,-2,-3],[5,-10,-15,-3]]) 
print(A)
c = np.array([0,0,0])
y = np.linalg.solve(A,c)
print(y)