Question $3$: Solve the following recurrence relations using iteration method.

$T(n)=3T(\frac{4n}{5})+(n)$

$T(1)=1$

$T(n)=3T(\frac{n}{3})+nlogn$

$T(1)=1$

$T(n)=T(n-1)+2^n$

$T(1)=1$