54-х=17+25 х÷5=26+144×х=52-16

54 - х = 17 + 25;

54 - х = 42;

- х = 42 - 54;

- х = - 12;

- х * (- 1) = - 12 * (- 1);

х = 12;

54 - 12 = 17 + 25;

42 = 42;

х : 5 = 26 + 14;

х : 5 = 40;

х = 40 * 5;

х = 200;

200 : 5 = 26 + 14;

40 = 40;

4 * х = 52 - 16;

4х = 36;

х = 36 : 4;

х = 9;

4 * 9 = 52 - 16;

36 = 36.