Obtain the tightest bound possible by giving the big$-$O notation for each of the following functions f$($n$).$ You do not need to show the calculation.

iv$.,f(n)=n^3**n^2+(n+2n{)}^2$

v$.f(n)=\frac{2n+5+n4}{n}$

vi$.,f(n)=n^2**(n+nlogn+1000)$