Was nationalism a cause of world war 1? Why or why not?

Yes, nationalism was a cause of World War 1 as the assassination of archduke Franz Ferdinand by Serbian nationalist Gavrilo Princip was one of the main reasons why the Austria-Hungary decided to wage war on Serbia.

Explanation:

Since the annexation of Bosnia and Herzegovina by Austria-Hungary in 1908 the situation on Balkan Peninsula was very tense.

Nationalism was rising, as no one wanted to accept the dominance of Austria-Hungary in the region.

Therefore, when Franz Ferdinand arrived in Sarajevo in 1914 this was seen as a provocation. Nationalist, led by the organization known as Young Bosnia decided to plan the  assassination of the Austrian prince.

i need the diagram.

8 - (2a + 7) = a + 40     distribute/multiply - into (2a + 7)

8 - 2a - 7 = a + 40

1 - 2a = a + 40       add 2a on both sides

1 = 3a + 40         subtract 40 on both sides

-39 = 3a       divide 3 on both sides

-13 = a

[proof]

8 - (2a + 7) = a + 40

8 - (2(-13) + 7) = -13 + 40

8 - (-26 + 7) = 27

8 - (-19) = 27

8 + 19 = 27

27 = 27