Here are two examples of assignments going wrong because of slang:
The Versailles Treaty of 1919 imposed severe economic and military
restrictions on Germany. The Germans had to make reparation payments
to the victorious allies, and the size and nature of the armed forces
permitted to Germany were limited. Many Germans felt that the Versailles
Treaty really put them down.
There are particular problems involved in communicating with patients
in geriatric care. Such patients are often confused and vulnerable,
which makes them resistant to advice. It is important not to get worked
up about this.
In both these examples, the writer has put in an expression which belongs
to informal speech rather than an academic assignment. Things like 'put
them down' and 'get worked up' are slang rather than formal language.
Other forms of slang include:
Swearing - Many Germans were pissed off about the Versailles
Local or dialect expressions - The Allies said to the
Germans, 'Youse lot are wrong.'
Words with a specialised meaning for young people - Modern
improvements in geriatric care are wicked.
None of these forms of slang should appear in an academic assignment.