800 + 72 : (23 - 15) = 809
1) 23-15 = 8
2) 72 : 8 = 9
3) 800 +9 = 809
7 × 8 - 4 × 7 + 200 = 228
1) 7 × 8 = 56
2) 4× 7 = 28
3) 56 - 28 = 28
4) 28 + 200 = 228
(51 - 47)×(15 - 7) + 100 = 132
1) 51 - 47 = 4
2) 15 - 7 = 8
3) 4×8 = 32
4) 32 + 100 = 132
90 × (17 - 9 ) +200 = 920
1) 17 - 9 = 8
2) 90 × 8 = 720
3) 720 + 200 = 920
д) условие некорректное , число пропущено
700+ 20... 3 +10 ... ??? = 800
возможно : 700 + 20 × 3 + 10 × 4 = 700 +60 +40 = 800
56: 8 + 70×4 = 287
1) 56 : 8 = 7
2) 70×4 = 280
3) 7 +280 = 287