Đáp án:
`n, (1/2 - (-2)/5 + 1/3 + 5/7 - (-1)/6) + (-4)/35 + 1/41`
`= 1/2 - (-2)/5 + 1/3 + 5/7 - (-1)/6 + (-4)/35 + 1/41`
`= 3/6 - (-14)/35 + 2/6 + 25/35 - (-1)/6 + (-4)/35 + 1/41`
`= (3/6 + 2/6 - (-1)/6) + (-(-14)/35 + 25/35 - 4/35) + 1/41)`
`= 6/6 + 35/35 + 1/41`
`= 1 + 1 + 1/41 = 2 + 1/41`
`= 82/41 + 1/41`
`= 83/41`