59. 300 - (90+70) + (86 - 46) 90:(10·9):(9:9) 0·8+7 0·(8+7) 91:13·7 84:(14·3)

Решим примеры:

1. $$300 - (90 + 70) + (86 - 46) = 300 - 160 + 40 = 140 + 40 = 180$$
2. $$90 : (10 * 9) : (9 : 9) = 90 : 90 : 1 = 1 : 1 = 1$$
3. $$0 * 8 + 7 = 0 + 7 = 7$$
4. $$0 * (8 + 7) = 0 * 15 = 0$$
5. $$91 : 13 * 7 = 7 * 7 = 49$$
6. $$84 : (14 * 3) = 84 : 42 = 2$$