I have water backing up into my kitchen sink and washer. This happens when the tub is draining and when the washer is being used. 5 years ago we had to have a root removed from the street. Could this be the problem again.

Open up the house cleanout and cycle the washer. If you see water backing up out of the cleanout then chances the roots have grown back. Have then linen snaked again.
If you wish to control roots RootX or Robics Foaming Root Killer that contain Dichlobrnic are two products you could try.
A less expensive way would be to call around to garden supply stores and ask for fine grain Copper Sulphate. Put a 1/2 pound in your toilet and flush it down. Repeat in 6 months.
Hope this helps and thank you for rating my answer, Tom