So really, in the last two to three videos, all we've done is we simplified the expression for the sum of the squared differences from the those n points to this line, y equals mx plus b.

实际上，在最后两到三个视频中，我们所做的只是简化了从这 n 个点到这条线的平方差之和的表达式， y 等于 mx 加 b。