Which of the following was a reason that US declared war in April of 1917?

- "the past is made of multitudinous items ranging from anything that can be collected, recollected or assessed to originate in the past. as such, the past is a gallimaufry of particulars that may not have been related in any way. however, the human mind seeks organization to understand concepts and other things. the human mind therefore seeks relationships in explaining and studying the past. history being a humanity, dictates that historians have to serve this human trait by bringing structure to details of the past. historians do this by creating interpretive frameworks that capture as many details as possible."

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the answer is jerusalem

the perimeter of a triangle is 69 cm. side a is 5 cm shorter than side b. side c is twice as long as side a. find the length of each side. i need to know how to do it in 2 equations.  

equations:

a = b-5

c = 2a

a + b + c = 69