The alphabet is $\backslash$Sigma $=\{$a$,$ b$,$ c$,+,=\}.$ The language is the same one as HW $4$ question $1$:

SUM $=\{$a

i

$+$bj

$=$ck

$|$i$,$ j$,$ k in N$,$ i $+$ j $=$ k$\}.$

Submit your CFG to the autograder under the name $1$b$.$cfg$.$