由a^2+b^2-6ab=0可知a^2+b^2=6ab则（a+b）^2 /(b-a)^2等于(a^2+b^2+2ab)/(b^2+a^2-2ab)等于（6ab+2ab）/(6ab-2ab) =8ab/4ab =2希望对你有帮助，祝你学习进步
