×:15=34-28 ×:(15-6)=23 ×-54=9*6 ×-54:9=6

× : 15 = 34 - 28;

х : 15 = 6;

х = 6 * 15;

х = 90;

90 : 15 = 34 - 28;

6 = 6;

× : (15 - 6) = 23;

х : 9 = 23;

х = 23 * 9;

х = 207;

207 : (15 - 6) = 23;

207 : 9 = 23;

23 =23;

х - 54 = 9 * 6;

х - 54 = 54;

х = 54 + 54;

х = 108;

108 - 54 = 54;

54 = 54;

× - 54 : 9 = 6;

х - 6 = 6;

х = 6 + 6;

х = 12;

12 - 54 : 9 = 6;

12 - 6 = 6;

6 = 6;