bertain

(1/8 + 1 3/5) / (6,9*10) = 0,025

1) 1/8 + 1 3/5 = 1/8 + 8/5 = (5+64)/40 = 69/40 = 1 29/40

2) 6,9*10 = 69

3) (1 29/40) / 69 = (69/40) / 69 = 1/40 = 0,025