What is the big-O notation of the following algorithm

Q1. What is the Big-O notation of the following algorithm (assume that all variables have been declared):
   for (int i=1; i<= n; i++)
       sum = sum + i * (i + 1);

Q2. What is the Big-O notation of the following algorithm (assume that all variables have been declared):
   for (int i = 5; i <= 2 * n; i++)
       System.out.println(2 * n + i - 1);

Q3. What is the Big-O notation of the following algorithm:
   for (int i = 1; i <= 2 * n; i++)
       for (int j = 1; j <= n; j++)
           System.out.println(2 * i + j);
               System.out.println(" ");


Q4. What is the Big-O notation of the following algorithm:
   for (int i = 1; i <= n; i++)
       for (int j = 1; j <= n; j++)
           for (int k = 1; k <= n; k++)
               System.out.println(i + j + k);


Q5. Each of the following expressions represents the number of inputs for
certain algorithms. Write them in Big O notation (e.g, n + 2 -> O(n)):

- n2 + 6n + 4
- 5n3 + 2n + 8
- (n2 + 1)(3n + 5)
- 5(6n + 4)
- n + 2log2n - 6
- 4nlog2n + 3n + 8

What is the Big-O notation of the following algorithm