What is the greatest prime factor of 4^17 - 2^28?
A. 2
B. 3
C. 5
D. 7
E. 11
Help!!! I get to 2^34 - 2^28 and don't know where to go from here...
Thanks! David
greatest prime factor
This topic has expert replies
2^34 - 2^28 = 2^6 * 2^28 - 2*28 = (2^6 - 1)*2^28
Now,
2^6 - 1 = 64 - 1 = 63 = 7*3*3
and the greatest prime factor is 7.
BTW, for some practice questions like this you can visit
https://www.testsandtutors.com/course/qu ... -and-Roots
Now,
2^6 - 1 = 64 - 1 = 63 = 7*3*3
and the greatest prime factor is 7.
BTW, for some practice questions like this you can visit
https://www.testsandtutors.com/course/qu ... -and-Roots
excuse me praxis, just wondering if you could help.
I went on to your link, signed up etc, started doing the section on exponentials and after answering the first question right, can not go any further (in other words, the site will not let me see the other questions). Do you have any idea why?
thx
I went on to your link, signed up etc, started doing the section on exponentials and after answering the first question right, can not go any further (in other words, the site will not let me see the other questions). Do you have any idea why?
thx
GMAX
That's very odd; the site shows at least 8 questions in that category. I'll see how long it takes to get fixed!
Want more practice GMAT questions? check out
https://www.testsandtutors.com/course/view.php/GMAT
https://www.testsandtutors.com/course/view.php/GMAT
A bunch of the categories were not displaying all the available questions, this is fixed!
Want more practice GMAT questions? check out
https://www.testsandtutors.com/course/view.php/GMAT
https://www.testsandtutors.com/course/view.php/GMAT