Let $f(x) = x^2 - x + 2010$. What is the greatest common divisor of $f(100)$ and $f(101)$?
First, realize that \(x^2-x=x(x+1)\). Also, realize that the prime factorization of 2010 is \(2\cdot3\cdot5\cdot67\). Therefore we can rewrite f(100) and f(101) like this:
\(f(100)=100\cdot99+2\cdot3\cdot5\cdot67 = 10(10\cdot99+3\cdot67) \\f(101)=101\cdot100+2\cdot3\cdot5\cdot67=10(10\cdot101+3\cdot67)\)
Since we cannot factor further, the answer to this question is \(\boxed{10}\)
I just realized i made a typo, because x^2-x = x(x-1), but the answer remains the same
Thanks textot
Here is another method:
\(f(100)=100^2-100+2010\)
\(f(101)=101^2-101+2010\\ f(101)=(100+1)^2-101+2010\\ f(101)=100^2+200+1-101+2010\\ f(101)=100^2-100+200+2010\\ f(101)=f(100)+200\\\)
Now my problem has changed to, what is the highest common factor of
\(100^2-100+2010 \qquad and \qquad 200\)
10 goes into both so I will divide by 10
\(1000-10+201 \qquad and \qquad 20\)
The last digit of the first one is 1. Nothing ending in 1 will have any common factors with 20, (it would have to end in a multiple of 2 or 5)
So
The hight common factor is 10.