6.90-(15+9):8 72:9+2.7 □⋅8=56 18+9⋅(13-7) 9.6-30:3 6⋅□=54 64-(28+4):4 28:7+5.6 □⋅9=63

Решаем примеры:

• 90 - (15 + 9) : 8 = 90 - 24 : 8 = 90 - 3 = 87
• 18 + 9 ⋅ (13 - 7) = 18 + 9 ⋅ 6 = 18 + 54 = 72
• 64 - (28 + 4) : 4 = 64 - 32 : 4 = 64 - 8 = 56
• 72 : 9 + 2 ⋅ 7 = 8 + 14 = 22
• 9 ⋅ 6 - 30 : 3 = 54 - 10 = 44
• 28 : 7 + 5 ⋅ 6 = 4 + 30 = 34

Решаем уравнения:

• x ⋅ 8 = 56 => x = 56 / 8 = 7
• 6 ⋅ x = 54 => x = 54 / 6 = 9
• x ⋅ 9 = 63 => x = 63 / 9 = 7

Ответ: 90-(15+9):8 = 87, 72:9+2.7 = 22, □⋅8=56 (7); 18+9⋅(13-7) = 72, 9.6-30:3 = 44, 6⋅□=54 (9); 64-(28+4):4 = 56, 28:7+5.6 = 34, □⋅9=63 (7).