Реши уравнения : 1) -0,8х-2,9=-2,9+5,8х 2) 1/3а-0,7=-3/5а-3,5 3) -3(2у-4)=7у-(-у-2) 4) -0,25-(-7в/12-1/4)=-(в/6+5/12)+в

Найдем корни.

1) -0,8 * х - 2,9 = -2,9 + 5,8 * х; 

-0.8 * x - 5.8 * x = -2.9 + 2.9;

-6.4 * x = 0;

x = 0.

2) 1/3 * а - 0,7 = -3/5 * а - 3,5; 

1/3 * a + 3/5 * a = -3.5 + 0.7;

5/15 * a + 9/15 * a = -2.8;

14/15 * a = -2.8;

2/15 * a = -0.4;

1/15 * a = -0.2;

a = -0.2 * 15;

a = -3.

3) -3 * (2 * у - 4) = 7 * у - (-у - 2); 

-6 * y + 12 = 7 * y + y + 2;

-6 * y + 12 = 8 * y + 2;

-6 * y - 8 * y = 2 - 12;

-14 * a = -10;

a = 10/14;

a = 5/7.

4) -0,25 - (-7 * b/12 - 1/4) = -(b/6 + 5/12) + b; 

-0.25 + 7/12 * b + 0.25 = -b/6 - 5/12 - b;

7/12 * b + b/6 + b = -5/12;

7/12 * b + 2/12 * b + 12/12 * b = -5/12;

21/12 * b = -5/12;

21 * b = -5;

b = -5/21.

5) (8 - k)/4 = (8 * k - 1)/5; 

4 * (8 * k - 1) = 5 * (8 - k);

32 * k - 4 = 40 - 5 * k;

32 * k + 5 * k = 40 + 4;

37 * k = 44;

k = 44/37.

6) (-11 + 2 * d)/(-0,19) = (3 - d)/0.07; 

-0.19 * (3 - d) = 0.07 * (-11 + 2 * d); 

-0.57 + 0.19 * d = -0.77 + 0.14 * d; 

0.19 * d - 0.14 * d = -0.77 + 0.57; 

0.05 * d = -0.2; 

5 * d = -20; 

d = -20/5; 

d = -4.