According to unit manual:
Detri costs 24000 metal and has 85800 HP
-7 silencer missiles cost 8000 for silencer + 7*18m/s*3min*60s/min= 30680 metal and do 11501,1 damage at the center of the explosion. 7*11501,1=80507,7<85800
so this wouldn't kill detri for 6680 higher metal cost, even if you manage to hit a moving detri with 7 consequential nukes. It looks better if you also hit other stuff around detri, which is likely, but the detri might be moving into your own base, which is likely, and you will be likely to hit your own stuff.
- 32 eos missiles cost 1200m for silo + 600m*32=20400m and do 3502,5*32=112080 damage, which is way more than 85800, so theoretically you would actually need 25 eoses, which would cost you 16,2k metal. This is again in the case you manage to hit a detri with 25 consequential eoses. This could be when you terraform it into a hole, or you could make this easier using 3-4 shockley's for 1,8k-2,4k metal. After which it would be cheaper to use some raiders, riots or an ultimatum to deal the damage.
But if you scout a detri and are planning to spend some thousands of metal on nukes or eoses, I suggest you use them to smash a hole in your opponents' defense line and pour some glaives/hermits/anything through it. For just 280 metal you can disable antinukes with a spy and nuke anywhere you want.