OK, then it says draw a single bond from each surrounding atom to the central atom, and subtract two valence electrons.

后将中心原子与其相邻原子之间,连上单键，然后减掉2个价电子。

麻省理工公开课 - 固态化学导论课程节选

They subtract this from the purchase price of the house and then you've got the cash to go and buy another house.

他们从售房价格里减去这个贷款余额,然后你就可以得到现金去买另一个房子

耶鲁公开课 - 金融市场课程节选

Subtract that from one, 100 multiply it by 100 and you have something between zero and 100.

用一减去后面那部分，再整体乘以,你就能得到0-100间的一些数值。

麻省理工公开课 - 固态化学导论课程节选

So to figure out bonding electrons, -- what we take is that number 18, which is our total number of electrons we need to fill valence shells, and we subtract it from our number of valence electrons, which is 10.

那么为了找出成键电子，我们将十八，也就是填满所有价壳层,所需要电子的总个数，减去我们所有的价电子的个数，也就是十。

麻省理工公开课 - 化学原理课程节选

There you are at the pearly gates and you look back on your life and you could, in principle, add up all the pleasures, add up all the pains, subtract the pains from the pleasures and ask yourself, "How good a life did I have?

当你站在天堂门口回顾一生时,你可以，在原则上，累加所有快乐，累加所有痛苦，从快乐中减去痛苦然后问自己，“我的一生到底有多好？

耶鲁公开课 - 死亡课程节选

And that's just to take 1 the principle quantum number l and subtract it by 1, and then also subtract from that your l quantum number.

主量子数,减去,再减去，量子数,你们可以对1s轨道来验证一下。

麻省理工公开课 - 化学原理课程节选

sb So in this case we would have 1 s a and 1 s b, and instead we would subtract one from the other, and what we would see is that instead of having additional, more wave function in the middle here, we've actually cancelled out the wave function and we end up with a node.

在这种情况下我们有1sa和，两者相减，我们可以看到不是在，中间有了额外更多的波函数，而是我们消掉了,波函数得到一个节点。

麻省理工公开课 - 化学原理课程节选

pxa So what happens when we add a 2 p a and we subtract from it a 2 p x b, or the same with a 2 p y a subtracting a 2 p y b, is that we're actually going to cancel out the wave function in the center, so we now have 2 nodal planes.

当我们用,减去2pxb时，或者是2pya减去2pyb时，我们会消去,中间的波函数，所以现在我们有两个节面。

麻省理工公开课 - 化学原理课程节选