answer and show me how you got to it with these following $2$ questions:

What are the transfer functions used in your system $($G$1,$ G$2,$ G$3$ and G$4)?$

Reduction of the roll system. How did you reduce the model according to block diagram reduction rules and what steps did you take $($i$.$e$.$ the manual approach used$)?$

System Information for Modelling $($it is a quadcopter$)$:

G$1($s$)=$ Front left motor.

G$2($s$)=$ Front right motor.

G$3($s$)=$ Rear left motor.

G$4($s$)=$ Rear right motor.

For a quadcopter all motors are identical which means,

G$1($s$)=$ G$2($s$)=$ G$3($s$)=$ G$4($s$)$

I have calculated G$1($s$)$ through MATLAB.

G$1($s$)=664/$s$^2+15\mathrm{.}08$ s $+169$

PID$($s$)=$ PID controller transfer function

do $=$ Output disturbance

F$($s$)=$ Sensor feedback transfer function, defined as:

F$($s$)1/0\mathrm{.}0105$s$+1$