Question

I need help pleaseeeee Prove that: 12^13–12^12+12^11 is divisible by 7 and 19. BTW in format ______*7*19 :D

Answer 1

Each term has a common divisor of $12^{11}$:

$12^{13}-12^{12}+12^{11}=12^{11}(12^2-12+1)=12^{11}\cdot133$

133 = 7*19, so the number in the blanks is $12^{11}$.