input: Write a function to evaluate a polynomial expression for a given value of x.
  assert evaluate_polynomial("2x2 + 3x + 4", 2) == 18
  assert evaluate_polynomial("5x2 + 6x + 1", 1) == 12
  assert evaluate_polynomial("3x2 + 2x + 5", 0) == 5
output: def evaluate_polynomial(expression, x):
      expression = expression.replace('^', '**').replace('x', f'({x})')
      return eval(expression)