这个简单的算术题答案是四。

The answer to this simple ___equation is four.

引入新的团队成员改变了项目成功的平衡因素。

Adding new team members altered the success ___equation for the project.

这个方程式需要用到代数知识来解决。

This ___equation requires algebra knowledge to solve.

老师让我们在实验报告里写下这个化学反应的方程式。

The teacher asked us to write down the chemical ___equation in the lab report.