1-1+7-9:7-1 hasilnya apo min?

1-1+7-9:7-1
= 1 – 1 + 7 – 1 2/7 – 1
= 6 – 1 2/7
= 4 5/7

(1+7)-(9+1)=8-10=-2
9:-(2+1)=9:-3=-3