25)
$[(-10)^{17} : (-10)^{14}]^2 : (-10^2)^2 -(-10)^0$ =
= $[(-10)^{17-14}]^2 : 10^{2·2} -1$ =
= $[(-10)^3]^2 : 10^4-1$ =
= $(-10)^{3·2} : 10^4-1$ =
= $10^6 : 10^4 -1$ =
= $10^{6-4}-1$ =
= $10^2-1$ =
= $100-1 = 99$
26)
$|-6|^3 : (-2)^3 -|-8|^2 : (-2)^2$ =
= $216 : (-8) -64 : 4$ =
= $-27-16$ =
= $-43$