My kitchen sink, bathroom sink and toilet won't drain the two sinks drain into the toilet and the toilet won't drain at all but the bathtub drains with no problems at all. Do u have any suggestions as to what the problem might be

Do you have a cellar? Your clog is before where the tub connects to the drain and after the toilet, probably very close to each other.

Yup, agree with Joypulv. You can look for a cleanout, or worst case, you'll need to pull the toilet and snake the drain from there. Note here, that if you have a flat enough roof you could also try snaking down the bathroom group vent...;)

Mark