How do we combine expressions in c#.

Question

public virtual IQueryable<T> AddExpression(Expression<Func<T, bool>> inputExpression)
{
   var parameter = Expression.Parameter(typeof(T));
   var e1 = Expression.Equal(Expression.Property(parameter, "RowStatusId"), Expression.Constant(1));
   var lambda = Expression.Lambda>(e1, parameter);

  //how can I combine this e1 with inputExpression ?
   //expression = Combine e1 and inputExpression

   return this.entities.Where(expression);
}