解：a/2=b/3≠0得3a=2b(5a-2b)/(a²-4b²)×（a-2b）=(5a-2b)/[(a+2b)(a-2b)]×（a-2b）=(5a-2b)/(a+2b)将3a=2b代入得原式=(5a-3a)/(a+3a)=1/2 愿对你有所帮助！
a=2/3b5*2/3b-9/2b-4b^2*(-4/3b)=10/3b-9/2b+3b=-7/6b+3b=11/6b
