Which statement correctly uses a description of time? The invention of the automobile began a new millennium.
The expansion of railroads marked the start of a new era.
The time from 1980 to 1989 was a century of economic growth.
The years 1900 to 1999 were a decade filled with many political changes.

the award is named for an american naval historian and theorist, rear admiral alfred thayer mahan, united states navy who, through his writing, provided stimulus and guidance to those who share in the defense of the nation.

1. it was caused by feudalism

2. charlemagne used christianity as a major cornerstone for his rule. cloisters were built all over the empire to act as centers for the (re)population of the vast european wilderness.

3. the europeans feared the next raid every time chetak

i'm not so sure about #6. but i hope i you with the first 3.

8 - (2a + 7) = a + 40     distribute/multiply - into (2a + 7)

8 - 2a - 7 = a + 40

1 - 2a = a + 40       add 2a on both sides

1 = 3a + 40         subtract 40 on both sides

-39 = 3a       divide 3 on both sides

-13 = a

[proof]

8 - (2a + 7) = a + 40

8 - (2(-13) + 7) = -13 + 40

8 - (-26 + 7) = 27

8 - (-19) = 27

8 + 19 = 27

27 = 27