Вычислите

а) - 20: (13+6 * (-3))

б) 3,84: (-1,6)

в) 4/5*3 5/6-0,8*1/3

/-дробь

*-умножение

А)

-20 : (13 + 6 * (-3)) = - 20 : (13 - 18) = - 20 : (-5) = 4,

б)

3,84 : (-1,6) = - 2,4,

в)

4/5 * 3 5/6 - 0,8 * 1/3 = 4/5 * 23/6 - 8/10 * 1/3 = 4/5 * 23/6 - 4/5 * 1/3 = 4/5 * (23/6 - 1/3) = 4/5 * (23/6 - 2/6) = 4/5 * 21/6 = 42/15 = 2 12/15 = 2 4/5 (или 2,8)

А) - 20: (13+6 * (-3)) = 4

1) 6 * (-3) = - 18

2) 13 + (-18) = - 5

3) - 20: (-5) = 4

б) 3,84: (-1,6) = 38,4: (-16) = - 2,4

в) 4/5*3 5/6-0,8*1/3=2 4/5

1) 4/5 * 3 5/6 = 4/5 * 23/6 = 23*4 / 5*6 = 23*2 / 5*3=46/15 = 3 1/15

2) 0,8*1/3=8/10 * 1/3=8/30

3) 3 1/15 - 8/30 = 3 2/30 - 8/30 = 2 32/30 - 8/30 = 2 24/30 = 2 4/5