Answer:
I did not understand
Step-by-step explanation:
Why is the question like that
Answer:
2.084...
Step-by-step explanation:
Just write an non repeating string of any numbers that you think of but not in a pattern which will lie between decimal value of your 2 numbers
Answer:
C is the most reasonable answer because to add the system of equations together, you must make sure that one of the terms (whether it be the x or y value) can cancel out.
Step-by-step explanation:

1) Since in the USA 8 x 10 ^9 messages are sent every month, that means that approximately 8 billion messages are sent.
2) We can Prime factorize it:
Note that on the right side we've picked only prime numbers. In this case, 2 and 5.
So we can rewrite 8 x 10^9 as prime factors.

3) Hence, the answer is:
let h= history books
science books = s
h=2s there are 2 times as many history as science so to get them equal we double the science
h+s=81 there are 81 total history and science books
2s+s=81 substitute 2s for h in the above equation
3s = 81 combine like terms
s = 27
There are 27 science books
h=2s
h=2(27)
h=54
there are 54 history books