trying to figure if I understand the basics of $\Bbb Z_7$ field ${}=\{1,2,3,4,5,6\}$ on the following equation:
$6x^3$ = $5$
I tried to reduce the coefficients in the equation -
$6x^3$ = $5$ => $6*6x^3 = 6*5$ => $36x^3 = 30$ => mod7 => $x^3 = 2$
From this stage $x^3 = 2$. I don't know how to continue.
Thanks in advance.
Hint:
Clearly $0$ is not a solution. On the other hand, for any $x\ne0$, lil' Fermat says that $x^6=1$, so $(x^3)^2=1$. What can you deduce for $x^3$, knowing we're in a field?