Решите уравнение: (3/5+3/4x)*20=42
3/5+3/4х=42/20 3/4х=42/20-3/5 3/4х=42/20-12/20 3/4х=30/20 х=30/20 : 3/4 х =30/20 * 4/3 х =10/5 * 1/1 х = 10 : 5 х = 2
Раскроем скобки 3/5*20=12 3/4х*20=15х 12+15х=42 15х=42-12 15х=30 х=2