'end' vs 'end up'

[Offroad]

Dear teachers

Is it possible to use the phrasal verb 'end up' in formal documents?

For example:

These books are difficult to read/understand and end up not being sold.

I wonder if 'end' alone would work too.

Many thanks.

Offroad

 

[Raymott]

Dear teachers

Is it possible to use the phrasal verb 'end up' in formal documents?

For example:

These books are difficult to read/understand and end up not being sold.

I wonder if 'end' alone would work too.

Many thanks.

Offroad

That sounds OK. You could say "remain unsold". You can't just say "end".