<span>The GCF is the number that is a factor of both (or all) of the numbers of a given set and which is the biggest factor of this kind (often the smaller number of the two)
7 and 14 have a greatest common factor of 7.
28 and 7 also have a GCF of 7, so the first two responses fit.
21 and 3 have a GCF of 3, so that isn't correct.
7 and 1 have a GCF of 1, so that's incorrect as well.</span>
I believe it is f(x)=5|x|
I suggest you get a second opinion, though
Answer:
it might be 8-9.5 correct me if i am wrong
Step-by-step explanation:
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.