Simple operation of 7 / 8-1 / 17 + 9 / 8-16 / 17

Simple operation of 7 / 8-1 / 17 + 9 / 8-16 / 17

7/8-1/17+9/8-16/17
=(7/8+9/8)-(1/17+16/17)
=2-1
=1