So P = A - B[Q1 + Q2] and profit is equal to

P=A-B[Q1+Q2]利润等于
--profit for Firm I is equal to P Qi-C Qi.

厂家1的利润等于PQi-CQi
And what we're told to do in backward induction is what?

逆向归纳法里叫我们怎么做来着
First of all, solve things out for Firm 2 taking Firm 1 as given,

首先把厂家1当做已知量解出厂家2
and then go back and solve for Firm 1.

然后再解出厂家1
So exactly the discussion we've just had informally,

所以之前我们的解法不太正式
we're now going to do more formally.

现在让我们更正式点
So backward induction tells us,

逆向归纳法告诉我们
solve for Firm 2 first, taking Q1 as given.

先解决厂家2的问题把Q1当已知量
What is that problem?

怎么解决这个问题
It's this sort of boring math problem,

这是个有些无聊的数学问题
it says maximize by choosing Q2 the profits of Firm 1,

要通过选择某个Q2值使厂家1的利润最大化