Final answer:
The first valid host on the subnetwork can be calculated using the IP address and subnet mask by setting all the host bits to 0 and leaving the network bits unchanged.
Step-by-step explanation:
The first valid host on the subnetwork that the node belongs to can be calculated using the IP address and subnet mask. The IP address is divided into two parts - the network ID and the host ID. The network ID identifies the specific subnet, while the host ID identifies the individual device within that subnet.
To find the first valid host ID, you need to set all the host bits to 0 and leave the network bits unchanged. This will be the first usable address in the given subnetwork.