How did westward expansion impact plain indians and fulfill manifest destiny?

Explanation:

During the Westward Migration, many Americans believed that the West was divinely ordained to be part of the United States, as part of manifest destiny Although populated by Indians and Latinos, the West was portrayed as empty land. The lure of cheap, fertile land led to Oregon fever, and settlers moved along the Overland Trails, enduring great physical difficulties.

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

explanation:

an oligopoly is a term used to clarify the structure of a particular market, industry, or organization. a market is considered oligopolistic or amazingly focused when it is shared between a few companies.