Question

Aflati toate perechile de numere naturale a, b astfel incat:

[tex] a^{b} -1 = 2^{4}*5

Observatie10^{n} = (2*5)^{n} = 2^{n} * 5^n} [/tex]

Answer 1

$a^{b}-1=2^4*5=80,deci, a^{b}=81,deci,9^2=81,obtinem,a=9,b=2$, sau 
$3^{4}=81,solutia,a=3,si,b=4,iar,81^1=81,ne,da,a=81,si,b=1.$, deci perachile sunt: (3;4); (9;2),si (81;1)