What is the greatest prime factor of 4^17-2^28?
a. 2
b. 3
c. 5
d. 7
e. 11
The answer is e ... how?
a. 2
b. 3
c. 5
d. 7
e. 11
The answer is e ... how?
i get 7
4^17-2^28
=>(2^2)^17-2^28
=>2^34-2^28
=>2^28(2^6-1)
=>2^28(64-1)
=>2^28*63
=>(2^28)*(3^2)*7 (broken down in the prime factors)
=>7 greatest prime
