Given a and b are vertical angles with m∠∠a = 20x + 10 and m∠∠b = 30x – 10. what is x?

Zachary has been trying to work on an essay for almost three hours, be he can't seem to focus for more than 15 or 20 minutes at a time. what should he do so that the quality of his work doesnt suffer because of poor concentration and lack of energy