It is useless to attempt to retaliate against the Socs because they are a socially privileged gang. Just for fun, Socs commit violence to greasers. Instead of being punished, they even get praised in the newspapers. So Ponyboy vowed never to get into any troubles.
You make 4/5b into 8/10b and subtract for om both sides. that leaves you with 1/10b. then it would be 6=1/10b. divide both sides by 1/10 . Your final answer is 60