一桶油，第一次倒出这桶油的一半，第二次倒出5千克，还剩20千克，这桶油原来有油多少千克？-L/[6n:P*o5z5@(h3Y(c0s
算式：提示6@7B9r+M:A9P)n0t-L/[6n:P*o5z5@(h3Y(c0s
答：这桶油原来有/b4l+u-g8t,^(Y'F9o3s千克。-L/[6n:P*o5z5@(h3Y(c0s