Because of one? +b？ -6ab = 0, what about A? +b？ -2ab=4ab, which means (a-b)? = 4ab……①

Answer? +b？ +2ab=8ab, which means (a+b)? = 8ab……②

Combine ① ② to get (a+b)? =8ab=2(a-b)？ That is: (a+b)? /(a-b)？ =2 ………③

From the title: a>b>0 is A+B > 0，b-a & lt； 0 so (a+b)/(b-a)

So: a+b)/(b-a)=-√2 (note: negative root sign 2, mathematical symbols are not easy to type, just understand)

There are two test sites for this problem, one is deformation, and the other is logo recognition. The positive value calculated upstairs is because the symbol is not considered. I hope I can help you. If you have any questions you don't understand, please ask me again.