Total Income of Pedro from Stock Sales can be calculated as below:
1) Gains from Piper Company
Selling Price of Shares $9000
Purchase Price of Shares $4300
Net Gains from Sale of Piper $4700
Loss From Troxel Shares
Sale Price of Troxel $6600
Purchase Price of Troxel $9700
Loss From Troxel $3100
Net Gain from Sale of Share $1600
Thus as per above Pedros Income will increase by $1600 due to the sale of both Troxel Company and Piper Company