I do not believe that any of us would exchange places with any other people or any other generation. The energy, the
faith, the devotion which we bring to this endeavour will
light our country and all who serve it and the glow from
that fire can truly light the world.
And so, my fellow Americans: Ask not what your country
can do for you - ask what you can do for your country.
Which statement best explains why the parallelism used in this excerpt is
effective

It's effective because it shows how we have a lot of devoted people, so we should ask what our country should do to improve the country.

the great wall of china worked as a defense for the feudal states of the zhou dynasty to the north. during the warring states period more walls were put up to defend the borders of the different kingdoms. it was semi successful because despite the wall, the mongols eventually conquered china also the great wall provided protection to the economic development and cultural progress, safeguarded the trading routes such as the silk road, and secured transmission of information and transportation. @jayxboof

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