Uhh, with basic windows functionality "yes" but I don't think it'll work right because the microphone will pickup the audio from the speakers and just you know, loop i until it's a loud screeching mess, unless you get one of those proper microphones for it that only pick up when they're right in front of your face.
It's easy enough to test out though.
1) right click the Sound/Volume icon in your task bar in the bottom right.
2) go to the recording devices.
3) right click your USB miccrophone and choose Properties
4) go to the Listen tab
5) check the Listen to this device box, and then click apply. THIS WILL IMMEDIATELY START BROADCASTING ANY MICROPHONE PICKUP
If it feedbacks just uncheck the box and hit apply again.
A laptops speakers probably also aren't great for broadcasting audio to a room, so you'll need some external ones.
Alternatively, you could project your voice louder/farther/more powerfully.
There may be a slight delay as well that makes it hard to talk because you hear what you just said a .5 second later.
I'm sure there's proper software for this as well but it probably aint cheap.
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