الحضور مهم والغياب مشكلة.

A natural Egyptian-style pronunciation is:

el-ḥoḍūr mohemm wel-ghiyāb moshkela

A few helpful notes:

• الـ is usually pronounced el- in Egyptian.
• و + الـ often comes out as wel-.
• ح in الحضور is a stronger, breathier h than English h.
• غ in الغياب is like a gargly gh, similar to the French r for many speakers.
• ة at the end of مشكلة is pronounced -a in pause, so moshkela.

Because Arabic often leaves out the verb to be in the present tense.

So:

• الحضور مهم = Attendance is important
• الغياب مشكلة = Absence is a problem

This is called a nominal sentence.

If you wanted the past, you would use a verb such as كان:

• الحضور كان مهم = Attendance was important

الـ is the definite article, like the in English.

So literally:

• الحضور = the attendance / the presence
• الغياب = the absence

But in Arabic, especially with abstract ideas, the definite article is often used where English just uses a general noun:

• الحضور مهم = Attendance is important
• not necessarily The attendance is important

So here الـ helps express the idea of attendance and absence as general concepts.

Because مهم here is the predicate adjective: it tells you something about الحضور.

In Arabic, when you say:

• الحضور مهم

the pattern is:

• definite subject + indefinite predicate

So:

• الحضور = the subject
• مهم = important

If you said الحضور المهم, that would no longer mean attendance is important. It would mean something like:

• the important attendance/presence

So مهم without الـ is exactly what you want here.

Arabic allows different kinds of predicates.

In this sentence:

• الحضور مهم uses an adjective as the predicate.
• الغياب مشكلة uses a noun as the predicate.

Both are completely normal.

So Arabic can say:

• X important
• Y a problem

without needing to keep the same part of speech in both halves.

Because مشكلة is a noun with its own fixed grammatical gender. It happens to be feminine.

That final ة usually marks a feminine noun.

Here, مشكلة means a problem, and it does not have to match الغياب in gender, because it is a noun, not an adjective agreeing with it.

Compare the logic in English:

• Absence is a problem

The word problem stays what it is. In Arabic, مشكلة likewise stays feminine because that is just the gender of that noun.

و means and.

It connects the two parts:

• الحضور مهم
• الغياب مشكلة

So the full sentence is basically:

• Attendance is important, and absence is a problem.

In Egyptian pronunciation, و before الـ often sounds like wel-, so:

• والغياب → wel-ghiyāb

It is very close to Standard Arabic in wording, but it is also perfectly understandable in Egyptian Arabic.

That is common. In Egyptian, especially in education, work, announcements, or semi-formal speech, you will often hear sentences that use standard-looking vocabulary but with Egyptian pronunciation.

So:

• Spelling: looks quite standard
• Pronunciation in Egypt: Egyptian
• Use in Egypt: natural, especially in formal or semi-formal contexts

They can mean either, depending on context.

In many everyday situations, especially school or work, this pair strongly suggests:

• الحضور = attendance
• الغياب = absence

But more generally, they can also mean:

• presence
• absence

Since they are paired together here, most learners will understand them as the attendance/absence pair.

In fully vocalized Standard Arabic, it could be written like this:

الحُضورُ مُهِمٌّ والغِيابُ مُشكِلَةٌ

But in normal Arabic writing, especially for Egyptian learners, you usually see it without the short vowels:

الحضور مهم والغياب مشكلة

For Egyptian Arabic:

• You generally do not pronounce case endings
• You usually do not write short vowels
• So the unvocalized form is the one you will see most often

That means for Egyptian purposes, the written sentence you were given is exactly the normal kind of form to learn from.