Use the recurrence tree method to solve the following

recurrence relation. Make sure to include a tree diagram and show all

steps in your answer.

$($a$)$ T$($n$)=2$T$($n $1)+2$n T$(1)=1$

$($b$)$ T$($n$)=3$T$($n $1)+1$ T$(1)=1$

$($c$)$ T$($n$)=2$T$($n$/2)+$ n$4$ T$(1)=1.$