you also have the forms above and below the isoelectric point in small quantities. You can't neglect this.
I finally solved this problem. After calculating the pI I setup an equation:
0.1M=[AA-]+[AA0]+[AA+]
Since I have the ratios from henderson equation you get:
0.1M = x+10.715x+x
solving for X gets all three amounts.
Thanks for all the help people. I was looking at it to be too complicated and did a lot more work.