Question

como resolvo isso?????

Answer 1

$x^6-7x^3+8=0\\\\\left(x^3\right)^2-7\left(x^3\right)+8=0\\\\k^2-7k+8=0\ \ \ \ \ onde\ \ k=x^3\\\\(k+1)(k-8)=0\\\\k=-1\ \ \ \ ou\ \ \ \ k=8\\\\x^3=-1\ \ \ \ ou\ \ \ \ x^3=8\\\\x=-1\ \ \ \ ou\ \ \ \ x=2$

Answer 2

$x^{6} - 7x^{3}+8=0 \\ (x^{3} )^{2} -7 (x^{3} ) + 8=0 \\ k^{2} -7k+8=0 \ onde\ k=x^3 \\ (k+1)(k-8)=0 \\ k=-1\ ou \ k=8$