I need help please as fast as you can

D.Members of an alliance had to defend each other if one went to war.

D.

Explanation:

How did Alliance Systems cause WWI? Secret alliances were formed prior to the outbreak of the war. After the Assassination of Franz Ferdinand the Archduke of Austria-Hungary the alliance systems went into effect leading to many nations protecting one another (i.e. Russia protecting Serbia from Austria-Hungary). Alliances prevented larger, stronger states from waging war on the smaller, weaker states.

answer

explanation

the given equation is

we can rewrite this as:

let

then the equation becomes:

the factors of 8 that sum up to -9 are {-1,-8}

we split the middle term with these factors to obtain,

we factor by grouping to obtain:

apply the zero product property to get:

but