MARKING BRAINLEIST BE QUICK PLS

Answer: 3j
Step-by-step explanation:
[tex]\mathrm{Factor\:}6j^2[/tex]
[tex]2\cdot \:3\cdot \:j\cdot \:j[/tex]
[tex]\mathrm{Factor\:}9j[/tex]
[tex]3\cdot \:3\cdot \:j[/tex]
The GCF are the factors that are in both expressions, in this case, the GCF it is 3 * j = 3j