Answer:
Step-by-step explanation:
25 200 giây
4n² - 15n + 14<span> is always the product of two numbers, for it to be prime number, one of these factors must be either 1 or -1.
Case n - 2 = 1
That would be n = 3
Then </span>4n² - 15n + 14<span> = 5 , which is prime.
Case n - 2 = -1
That would be n = 1
Then </span>4n<span>² - 15n + 14 = 3, which is also prime.
Case 4n - 7 = 1
That would be n = 2 and that makes other factor (n-2) zero so it's not prime
Case 4n-7 = -1
That would be n = 3/2 which is not integer, so </span>4n<span>² - 15n + 14 will not be interger.
For any other n values, </span>4n<span>² - 15n + 14 will be composite number since it is product of two factors.
Therefore we are left with n = 1 and n = 3; only two values of n.</span>
Answer:
A5#A
Step-by-step explanation:
Answer:
20.0%
Step-by-step explanation:
The last 30 presidents of America starts from the 16th president, Abraham Lincoln and ends with the current and 45th president, Donald Trump.
The presidents that are 60 and above years during this period include
Donald Trump, Goerge H. W. Bush, Roland Regan, Gerald Ford, Dwight D. Eisenhower and Harry S. Truman.
Making 6 of them out of 30
The percentage is given by
Number of presidents aged 60 and above×100/Total number of presidents
6×30/100=20%
