360/(12-х)-15=25
360/(12-х) = 25+15
360/(12-х) = 40
12-х = 360/40
12-х = 9
х = 12-9
х= 3
Проверка:
360/(12-3)-15 = 360/9 - 15 = 40-15 = 25
480/(34-x/7)=16
16• (34 - х/7) = 480
34 - х/7 = 480/16
34 - х/7 = 30
х/7 = 34-30
х/7 = 4
х= 4•7
х = 28
Проверка:
480 / (34 - 28/7) = 480 / (34-4) = 480/30 = 16