answer: 1/16
to have an equation you need an "=" somewhere. since I don't see one, I will simplify the expression.
[tex] {4}^{6} \times {4}^{ - 8} [/tex]
same base number, so we can add the exponents:
[tex] {4}^{6 + (- 8)} [/tex]
[tex] {4}^{ - 2} [/tex]
and our answer is 1/4^2=1/16.