You've got to juggle the two equations, multiply that by 4, multiply that by 3, add and subtract and so on.

同时处理这两个方程,这个两边乘以4,另一个两边乘以3,将两方程相加或相减求出答案

耶鲁公开课 - 基础物理课程节选

And since we don't have to charge compensate, we can add or subtract neutrons at liberty.

因为我们没有电荷补偿，我们就可以随意地加上火减少中子。

麻省理工公开课 - 固态化学导论课程节选

But all of you in this room probably remember what we technically call the base 10 system or decimal system because back in grade school or the like, you learned to count and add and subtract numbers by way of columns.

但是，在座的每一位可能都记得,这在小学的时候学的,以10为进制的系统或者十进制系统,通过数列方式学习数数和加减法。

哈佛公开课 - 计算机科学课程节选