Выполните действия: а) 703-21×(361-349), б) 2346 : (209-186) ×15, в) 6422-24× (372:12),...

А)
$703 - 21 \times (361 - 349) = \\ = 703 - 21 \times 12 = \\ = 703 -252 = \\ = 451$
б)
$2346 \div (209 - 186) \times 15 = \\ = 2346 \div 23 \times 15 = \\ = 102 \times 15 = \\ = 1530$
в)
$6422 - 24 \times (372 \div 12) = \\ = 6422 - 24 \times 31 = \\ = 6422 - 744 = \\ = 5678$
г)
$2678 \div (506 - 480) + 297 = \\ = 2678 \div 26 + 297 = \\ = 103 + 297 = \\ = 400$