∵a:b:c=2:3:5,
设a=2k,b=3k,c=5k,
∴a+c-bb=2k+5k-3k3k=43.
故答案为:43.
计算: (1)x(y﹣1)﹣y(x﹣1);
(2)(x﹣3y)(x+3y)﹣(x﹣3y)2.
汽包事故放水在联锁投入的情况下何时开关?