（1）（m²-3m）/9-m²=m(m-3)/(3+m)(3-m)=-m/(m+3)（2）(3a²-ab)/（9a²-6ab+b²）=a(3a-b)/(3a-b)²=a/(3a-b)=9/35(3)（a²-b²）/（a²+ab）=(a+b)(a-b)/a(a+b)=(a-b)/a（4...