from sympy import S, Eq, solve
vf, d, a, vi, t = S('vf d a vi t'.split())
equations = [Eq(vf, vi + a * t), Eq(d, vi * t + a * t ** 2 / 2), Eq(a, 10),
    Eq(d, 60), Eq(vi, 5)]
solve(equations)
solve(equations, [a, t, vi, vf, d])
Solving Systems of Equations with SymPy