# import sympy 
from sympy import * 
  
n = symbols('n', integer = True)
expr = factorial(n)/factorial(n - 3)
print("Expression = {}".format(expr))
   
# Use sympy.combsimp() method 
simple_expr = combsimp(expr)  
      
print("Simplified Expression : {}".format(simple_expr))  

Expression = factorial(n)/factorial(n - 3)
Simplified Expression : n*(n - 2)*(n - 1)

# import sympy 
from sympy import * 
  
n, k = symbols('n k', integer = True)
expr = binomial(n + 1, k + 1)/binomial(n, k)
print("Expression = {}".format(expr))
   
# Use sympy.combsimp() method 
simple_expr = combsimp(expr)  
      
print("Simplified Expression : {}".format(simple_expr))  

Expression = binomial(n+1, k+1)/binomial(n, k)
Simplified Expression : (n + 1)/(k + 1)