b分之2乘以根号ab五次方乘以（-2分之3根号a³b）乘以3根号b分之a
2/b×√﹙ab^5﹚×﹙﹣3√﹙a³b﹚/2﹚×3√﹙a/b﹚
=﹣9a²b√﹙ab﹚