Equations

import sympy as sy

x1, x2 = sy.symbols("x1 x2")

equations = [
    sy.Eq( 2*x1 + 1*x2 ,  10 ),
    sy.Eq( 1*x1 - 2*x2 ,  11 )
]

print sy.solve(equations)
# Result: {x1: 31/5, x2: -12/5}

import sympy as sy

x, y = sy.symbols("x y")

# nsolve needs the (in this case: two) equations, the names of the variables 
# (x,y) we try to evaluate solutions for, and an initial guess (1,1) for the 
# solution
print sy.nsolve((x**3+sy.exp(y)-4,x+3*y),(x,y),(1,1)) 

[  1.50281519319939]
[-0.500938397733129]

import sympy as sy

# Symbols have to be defined before one can use them
x = sy.S('x')

# Definition of the equation to be solved
eq=sy.Eq(x**2 + 2, 6)

#Print the solution of the equation
print sy.solve(eq)

[-2, 2]