15/17-1/13
Let's calculate: 1517 -113
15×13 -1×1717×13
ℹ15×13 = 195‖-1×17 = -17‖17×13 = 221
195 -17221
ℹ195 -17 = 178
▶Result:   178221
The approximate value of: 178221 equals:
▷ ≈ 0.8054