1) - 3 (а-2) + 6 (а-4) - 4 (3 а+2) = 2) 4 (с-1) - 7 (с+5) - 2 (3 с+7) = 3) 0.9 (b-5) - 0.8 (b-2) = 2,3 4) (6,2x+9,3) (4x-3.6) = 0 5) 0.4 (a-4) - 0.3 (a-3) = 1.7 6) (4.2x-6.3) (5x+5.5) = 0

Упростим выражения:

1) - 3 * (а - 2) + 6 * (а - 4) - 4 * (3 * а + 2) = - 3 * a + 6 * a - 24 - 12 * a - 8 = - 9 * a - 32;

2) 4 * (с - 1) - 7 * (с + 5) - 2 * (3 * с + 7) =

3) Решим уравнения:

0.9 * (b - 5) - 0.8 * (b - 2) = 2,3;

0.9 * b - 4.5 - 0.8 * b + 1.6 = 2.3;

0.1 * b = 0.6;

b = 6;

4) (6,2 * x + 9,3) * (4 * x - 3.6) = 0;

{ 6.2 * x = - 9.3;

4 * x = 3.6;

{ x = - 93/62;

x = 0.9;

5) 0.4 * (a - 4) - 0.3 * (a - 3) = 1.7;

0.4 * a - 0.16 - 0.3 * a + 0.9 = 1.7;

0.1 * a - 0.7 = 1.7;

0.1 * a = 2.4;

a = 24;

6) (4.2 * x - 6.3) * (5 * x + 5.5) = 0;

{ 4.2 * x - 6.3 = 0;

5 * x + 5.5 = 0;

{ x = 63/42;

x = - 5.5/5;

{ x = 3/2;

x = - 1.1.