令k1(2a-3b)+k2(2b-2c)+k3(c-a)=5a-2b-9c,解出k1=6,k2=8,k3=7令3a+2b/2a-3b=3b+c/2b-2c=2c-4a/c-a=k设所求式子=n则5a-2b-9c=(a+2b+3c)/n则k1（3a+2b)+k2(3b+c)+k3(2c-4a)=k(5a-2b-9c)=k/n(a+2b+3c)-10a+36b+22c=k/n(...