trade off

trade-off :a balance between two opposing things, that you are willing to accept in order to achieve something.  可数名词，权衡，折中。

You cannot have your cake and eat it too.鱼与熊掌不可兼得。

Deciding which modules to display in the Phenomenal English WeChat menu is a matter of trade-off.

Life is full of trade-offs. You cannot have your cake and eat it too.

a trade-off between A and B

There must be a trade-off between quality and quantity for many manufacturers.    （a trade-off）

But leaving the EU inevitably involves difficult trade-offs. （difficult trade-offs）

翻译：   

这个决定是权衡效率和成本后的结果。    The decision is a trade-off between efficiency and cost.

（这个决定是对效率和成本的权衡。如果我翻译的话可能会把结果也给放进来进行翻译，就会显得有些多余，不如给出的参考翻译简洁。）

造句：As a student, there must be a trade-off between studies and hobbies.