$1.$ Use MATLAB to solve Pre$-$work Problem $1.$

$2.$ Use MATLAB to solve Pre$-$work Problem $2$ using a single MATLAB command.

$3.$ Use MATLAB to solve Pre$-$work Problem $3.$ Also use various combinations of

$()$

$1$ G s

and

$()$

$2$ G s

to find

$()3$ G s $,()$

$4$ G s

and

$()$

$5$ G s

$.$ Various combinations implies