упрощение выражений:

23*15+15*77

67*58+33858

340*7+16*70

250*61-25*390

79*21-69*21

55*682-45*682

7300*3+730*70

500*38-50*80

А) 23*15 + 15*77 = 15 * (23 + 77) = 15*100 = 1500

б) 67*58 + 33*58 = 58 * (67 + 33) = 58*100 = 5800

в) 340*7 + 16*70 = 7 * (340 + 16*10) = 7*500 = 3500

г) 250*61 - 25*390 = 25 * (10*61 - 390) = 25*220 = 5500

д) 79*21 - 69*21 = 21 * (79 - 69) = 21*10 = 210

е) 55*682 - 45*682 = 682 * (55 - 45) = 682*10 = 6820

ж) 7300*3 + 730*70 = 730 * (10*3 + 70) = 730*100 = 73000

з) 500*38 - 50*80 = 50 * (10*38 - 80) = 50*300 = 15000