kono mondai ga muzukasikereba, betu no mondai wo saki ni tokimasu.

Yes. 難しければ is the conditional form of the い-adjective 難しい (difficult), and it means if it is difficult.

So:

• 難しい = difficult
• 難しければ = if it is difficult

In this sentence, この問題が難しければ means:

• if this problem is difficult

This 〜ければ form is a common way to make an if clause, especially in slightly more neutral or written-style Japanese.

For an い-adjective, you usually:

1. remove the final い
2. add ければ

So:

• 難しい
• → remove い
• → 難し
• → add ければ
• → 難しければ

This pattern works with many い-adjectives:

• 高い → 高ければ = if it is expensive/high
• 安い → 安ければ = if it is cheap
• 早い → 早ければ = if it is early/fast

Here, が marks 問題 as the thing that has the property difficult.

So:

• 問題が難しい = the problem is difficult

Using が here is very natural because the sentence is talking about whether this problem is difficult.

If you used は, it would sound more like setting the problem up as a topic or contrast:

• この問題は難しければ...

That is less natural in this exact sentence unless you are deliberately contrasting it with something else.

A simple way to think about it:

• が often marks the item being described
• は often marks the topic or creates contrast

So この問題が難しければ is the standard choice here.

Because they play different roles in the sentence.

First one:

• この問題が難しければ
• 問題 is the thing being described as difficult
• so it takes が

Second one:

• 別の問題を先に解きます
• 問題 is the thing being solved
• so it takes を

In other words:

• が = subject of is difficult
• を = direct object of solve

This is a very common pattern in Japanese: the same noun can take different particles depending on its role.

別の means another or a different.

So:

• 別の問題 = another problem / a different problem

The word 別 often connects to a noun with の in standard Japanese:

• 別の方法 = another method
• 別の日 = another day
• 別の問題 = another problem

You may sometimes hear 別な, but 別の is the more standard and common form for learners to use.

先に means first, ahead of that, or before that.

In this sentence:

• 別の問題を先に解きます
• = I’ll solve another problem first

The idea is:

• if this problem is difficult,
• I will do another one before doing this one

先 means ahead / previous / earlier, and に turns it into an adverbial expression here.

Common examples:

• 先に行きます = I’ll go first
• 先に食べてください = Please eat first
• 先に宿題をします = I’ll do homework first

Japanese very often omits the subject when it is obvious from context.

In English, you usually need to say:

• I’ll solve another problem first
• or we’ll solve another problem first

In Japanese, if the speaker is clearly talking about their own action, you can simply say:

• 別の問題を先に解きます

The subject is understood from context, and it is often something like:

• I
• we
• you

depending on the situation.

This kind of omission is one of the most common things English speakers notice in Japanese.

It is the Japanese non-past form.

Japanese does not separate present and future the way English often does. So 解きます can mean:

• solve
• will solve
• am going to solve

In this sentence, because it follows an if clause, it is most naturally understood as future:

• If this problem is difficult, I’ll solve another problem first.

So even though the verb form is not a special future tense, the meaning here is future.

この is the form used when you want to say this + noun directly.

So:

• この問題 = this problem

Compare:

• これ = this one
• この問題 = this problem

Using これの問題 would usually not be the normal way to say this problem. A beginner-friendly rule is:

• これ stands alone
• この must be followed by a noun

Examples:

• これは難しい = This is difficult.
• この問題は難しい = This problem is difficult.

Yes, a very natural alternative is:

• この問題が難しかったら、別の問題を先に解きます。

That also means If this problem is difficult, I’ll solve another problem first.

The difference is subtle:

• 〜ければ can sound a bit more general, formal, or matter-of-fact
• 〜たら is very common in everyday conversation

So both are possible, but 難しければ is a nice standard textbook-style conditional.

The sentence breaks down like this:

• この問題が = this problem
• 難しければ = if it is difficult
• 別の問題を = another problem
• 先に = first
• 解きます = solve / will solve

So the structure is:

• [If clause], [main clause].

More literally:

• If this problem is difficult, (I) will solve another problem first.

This is a very common Japanese pattern:

• Aければ、B
• If A, then B

Yes, Japanese word order is more flexible than English, as long as the particles make the roles clear.

For example, these are both natural:

• 別の問題を先に解きます。
• 先に別の問題を解きます。

Both mean roughly:

• I’ll solve another problem first.

The version in your sentence, 別の問題を先に解きます, is perfectly natural.

A useful rule is:

• the verb usually comes at the end
• other elements can move around more freely than in English

The comma marks a pause between the if clause and the main clause:

• この問題が難しければ、別の問題を先に解きます。

It helps readability, especially in longer sentences.

Japanese commas are often more flexible than English commas, but here it is very natural because the first part sets up the condition, and the second part gives the result/action.

So the comma is not changing the grammar; it just makes the sentence easier to read.

It often suggests that, but it does not explicitly say so.

What the sentence directly says is only:

• If this problem is difficult, I’ll solve another problem first.

Because of 先に (first), many listeners will naturally infer:

• maybe the speaker plans to return to this difficult problem later

But that is an implication from context, not something stated outright.

If you wanted to say it more explicitly, you could add something later like:

• あとでこの問題を解きます = I’ll solve this problem later