(13.9+259.1)*0.85-10x=100.1
раскроем скобки
11.815+220.235-10x = 100.1
-10x+131.95 = 0
10x-131.95 = 0
10x = 131.95
x = 13.195
(13.9+259.1)*0.85-10x=100.1
раскроем скобки
11.815+220.235-10x = 100.1
-10x+131.95 = 0
10x-131.95 = 0
10x = 131.95
x = 13.195