Начнем с открытия скобок:

(0.5x + 4) * 5 + 12.5x = 95;

0.5x * 5 + 4 * 5 + 12.5x = 95;

2.5x + 20 + 12.5x = 95;

2.5x + 12.5x = 95 - 20;

15x = 75;

x = 75 : 15;

x = 5.