I did the problem and I got negative 4 over 9
The sum of the first n odd numbers is n squared! So, the short answer is that the sum of the first 70 odd numbers is 70 squared, i.e. 4900.
Allow me to prove the result: odd numbers come in the form 2n-1, because 2n is always even, and the number immediately before an even number is always odd.
So, if we sum the first N odd numbers, we have

The first sum is the sum of all integers from 1 to N, which is N(N+1)/2. We want twice this sum, so we have

The second sum is simply the sum of N ones:

So, the final result is

which ends the proof.
Answer:
Yes, one of a rhombus's properties is that the diagonals bisect vertex angles.
Answer:
for 3644 produced books the costs will be the same.
Step-by-step explanation:
x = number of books
f(x) = production method 1 costs
g(x) = production method 2 costs
f(x) = 11.75x + 57077
g(x) = 21.25x + 22459
for what number of books (x) will that be the same ?
11.75x + 57077 = 21.25x + 22459
34618 = 9.5x
x = 34618 / 9.5 = 3644