-3 + (8/31) + 4 + 1 + (-6) + 2 + 9
= -3 + 8/31 + 4 + 1 - 6 + 2 + 9
= -3 + 8/31 + 4 + 1 + 2 + 9 - 6
= -3 + 8/31 + 7 + 1
= -3 + 8/31 + 8
= -3 + 8/31 + (248/31)
= -3 + (8 + 248)/31
= -3 + 256/31
= (256-93)/31
= 163/31

Therefore, -3 + 8/31 + 4 + 1 + (-6) + 2 + 9 = 163/31.