X+(X+13.95)=26.55
X+X+13.95=26.55
2X+13.95=26.55
2X=26.55-13.95
2X=12.60
X=6.30
X+13.95
=6.30+13.95
=20.25
答:字典的單價是20.25元,鋼筆的單價是6.30元。