1. Вычислим:
a) $$-28+12 \cdot 7 = -28 + 84 = 56$$
б) $$-21 + 84:7 = -21 + 12 = -9$$
в) $$-11 \cdot 7 + 42 = -77 + 42 = -35$$
2) $$19 \cdot 4 - 48 = 76 - 48 = 28$$