Big Oh notation complexity. 4 parts. Answer gets immediate upvote

For each of the following expressions of code/time complexity of algorithms, express the big oh upper bound that gives the tightest upper bound of expression

While it is true that O(n^3) is an upper bound of 3x^2 + 5N - 8, it will not give you points towards the homework since if is not the tightest upper bound you could express.

Once you have determined big-O bounds for each expression, order the expressions from the slowest growing (best algorithm, takes least amounf ot time to execute) to the fastest growing.

1) n^3(log2n +5) + logn2 -20

2) 532n + (1/25)n^2 + 10nlog2n - 20n

3) 10log2n + (nlog2n)/(20) + 33nlog2n)

4) 10^6n^2 + (1/1000)2^n + 33nlog2n