Решите уравнение -15x+31=-7+4x 7(2+y)-3y=5y-6 2(4-9d)-(2d+3)=-8(4-d)+3(1+2d)

Найдем корешки уравнений:

1) -15 * x + 31 = -7 + 4 * x; 

-15 * x - 4 * x = -7 - 31;

15 * x + 4 * x = 31 + 7;

x * (15 + 4) = 36;

19 * x = 36;

x = 36/19.

2) 7 * (2 + y) - 3 * y = 5 * y - 6; 

7 * 2 + 7 * y - 3 * y = 5 * y - 6;

14 + 4 * y = 5 * y - 6;

4 * y - 5 * y = -6 - 14;

-y = -21;

y = 21.

3) 2 * (4 - 9 * d) - (2 * d + 3) = -8 * (4 - d) + 3 * (1 + 2 * d); 

8 - 18 * d - 2 * d - 3 = -32 + 8 * d + 3 + 6 * d; 

-20 * d + 5 = 14 * d - 29; 

-20 * d - 14 * d = -29 - 5; 

-34 * d = -34; 

34 * d = 34; 

d = 34/34; 

d = 1.