4/5-1/7
Let's evaluate: 45 -17
4×7 -1×55×7
ℹ4×7 = 28‖-1×5 = -5‖5×7 = 35
28 -535
ℹ28 -5 = 23
▶Result:   2335
The numeric value of: 2335 is:
▷ ≈ 0.6571