What this really means is in a given time, the change in this quantity is a times the change in this quantity.

这里的真正含义是在给定的一段时间内,这个量的变化量等于,a乘以这个量的变化量

耶鲁公开课 - 基础物理课程节选

As long as we understand that, we can do this cancellation and this says on the left-hand side the change in the quantity v square over 2 is a times the change in the quantity x.

只要我们明白这一点,我们就可以这样做简化,在等号左边,v^/2的变化量,为a乘以x的变化量

耶鲁公开课 - 基础物理课程节选