Решите уровнения. 1) 3х+5х+7х=60; 2) 19х-12х=4,9; 3) 8х+3х+1,6=1,93; 4) 14х-4х-2,8=11,2.

Вычислим корешки уравнений.

1) 3 * х + 5 * х + 7 * х = 60;  

x * (3 + 5 + 7) = 60; 

x * (8 + 7) = 60; 

15 * x = 60; 

x = 60/15; 

x = 4. 

2) 19 * х - 12 * х = 4,9; 

x * (19 - 12) = 4.9;

x * 7 = 4.9;

x = 4.9/7;

x = 0.7.

3) 8 * х + 3 * х + 1,6 = 1,93; 

x * (8 + 3) + 1.6 = 1.93;

11 * x + 1.6 = 1.93;

11 * x = 1.93 - 1.6;

11 * x = 0.33; 

x = 0.33/11;

x = 0.03.

4) 14 * х - 4 * х - 2,8 = 11,2; 

x * (14 - 4) - 2.8 = 11.2; 

10 * x - 2.8 = 11.2; 

10 * x = 11.2 + 2.8; 

10 * x = 14; 

x = 14/10; 

x = 1.4.