+118723 Good try anon but you multiplied in the 3rd line instead of dividing.
$$\\498-3x^8=216\\
-3x^8=-282\\
x^8=94\\
x=\pm\; 94^{1/8}\\$$
$${{\mathtt{94}}}^{\left({\frac{{\mathtt{1}}}{{\mathtt{8}}}}\right)} = {\mathtt{1.764\: \!578\: \!493\: \!147\: \!236}}$$
$$x\approx \pm\; 1.76457849314$$
498-3*x^8=216
-3X^8=216-498
-3X^8=-282 //*-3
X^8=846 // ROOT 8
X=2.322315898...=2.3
answer 2.3
+118723 Good try anon but you multiplied in the 3rd line instead of dividing.
$$\\498-3x^8=216\\
-3x^8=-282\\
x^8=94\\
x=\pm\; 94^{1/8}\\$$
$${{\mathtt{94}}}^{\left({\frac{{\mathtt{1}}}{{\mathtt{8}}}}\right)} = {\mathtt{1.764\: \!578\: \!493\: \!147\: \!236}}$$
$$x\approx \pm\; 1.76457849314$$
