Explain the significance of 2 of these cases and their consequences to the development of American history.

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d) post-world war i

simplify brackets

8 - 2a - 7 = a + 40

simplify 8 - 2a - 7 to -2a + 1

-2a + 1 = a + 40

add 2a to both sides

1 = a + 40 + 2a

simplify a + 40 + 2a to 3a + 40

1 = 3a + 40

subtract 40 from both sides

1 - 40 = 3a

simplify 1 - 40 o -39

-39 = 3a

divide both sides by 3

-39/3 = a

simplify 39/3 to 13

-13 = a

switch sides

a = -13

a agree i agree becuase it is very importnat for example it can tlel you about your past for exmaple   the first culture was the semerians which people are sitll tryignt o uncover there secrets the wall is just anohter treasure that has thousnads of secrets in it to be uncovered