-8⅙ + 2⅔ = -8⅙ + 2⁴/₆ = -5³/₆ = -5½
2 i 2/3= 2 i 4/6 więc -8⅙ + 2 i 4/6= (-5 i 1/2)
-8⅙ + 2⅔ = -82/3 + 2 2/3 = -6 4/3 = -5 1/3