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

Вычислим корни 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.