CIS $560$ Final Exam $-\frac{12}{18}\frac{?}{2023}$

the following two languages $L_1$ and $L_2$ over the alphabet $\{a,b,c\}$ :

$L_2=\{a^n{b}^{n}c|n1\}$

$($a$)$ Design a context$-$free grammar $G_1$ for the star of language $L_1.$

$($b$)$ Design a context$-$free grammar $G_2$ for the concatenation of language $L_1$ and $L_2.$