12x^4+18x^2
= 3x^2 (4x^2+6)
Thus, the greatest common factor is 3x^2
You must calculate how many ways can 2 people be selected from 65.
The formula is:
n! / r! * (n-r)! =
65! / 2! * 63! =
65*64*63! / 2 * 63! =
65*64 / 2 =
2,080 handshakes
Source:
http://www.1728.org/combinat.htm
Answer:
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Step-by-step explanation:
