3. Вычислите: 2/3 – 5/18 : 15/27.

2/3 – 5/18 : 15/27 = 2/3 – (5/18 · 27/15) = 2/3 – (5/18 · 3/2) = 2/3 – 15/36 = 2/3 – 5/12 = 8/12 – 5/12 = 3/12 = 1/4