Why does toilet water flow into tub

U have blockage in waste line.

Use a toilet snake and try to clear it out.

If this does not work, will have to run snake through tub overflow.

Chuck

how do i fix problem toilet every time i flush it slow drians and fills up in my bathtub

You have a blockage In the toilet drain line that must be snaked. This can be addressed in one of three ways.
1) Pull the toilet and shake from there **OR**
2) Snake from the baths lavatory roof vent.
3) Snake from the tub waste and overflow
Keem. You have posted the same question three times, That's unnecessary and clutters up the page. Tom