Решаем линейное уравнение:

4x - 5.5 = 5x - 3 * (2x - 1.5);

4x - 5.5 = 5x - 6x + 4.5;

4x - 5x + 6x = 4.5 + 5.5;

x(4 - 5 + 6) = 10;

5x = 10;

x = 10 : 5;

x = 2.