Решить уравнения .Очень надобно 1....3х-х-2=0 2....4х+х-5=0 3...(x-6)=(7-x) 4...x-4(9-x)=3x+2 5...-5x+9(-1+2x)=9x-1 6...4x+6x-2=(x-1) 7...2x+11x+34=(x+6)

1) 3х - х - 2 = 0;

3х - х = 2;

2x = 2;

x = 2 : 2;

x = 1.

2) 4х + х - 5 = 0;

D = b^2 - 4 * a * c;

D = 1^2 - 4 * 4 * (-5) = 1 + 16 * 5 = 1 + 80 = 81.

D = 81 = 9.

x1 = (-b + D)/2a = (-1 + 9)/2 * 4 = 8/8 = 1.

x2 = (-b - D)/2a = (-1 - 9)/2 * 4 = -10/8 = -1,25.

3) (x - 6) = (7 - x);

x - 12x + 36 = 7 - x;

x - 12x + x = 7 - 36;

x - 11x = -29;

x - 11x + 29 = 0;

D = (-11)^2 - 4 * 1 * 29 = 121 - 116 = 5

D = 5 = 2,24.

x1 = (-b + D)/2a = (11 + 2,24)/2 = 13,24/2 = 6,62.

x2 = (-b - D)/2a = (11 - 2,24)/2 = 8,76/2 = 4,38.

4) x - 4 * (9 - x) = 3x + 2;

x - 36 + 4x = 3x + 2;

5x = 3x + 2 + 36;

2x = 38;

x = 38 : 2;

x = 19.

5) -5x + 9 * (-1 + 2x) = 9x - 1;

-5x - 9 + 18x = 9x - 1;

-5x - 9x + 18x = 9 - 1;

-16x + 18x = 8;

2x = 8;

x = 8 : 2;

x = 4.

6) 4x + 6x - 2 = (x - 1);

4x + 6x - 2 = x - 2x + 1;

4x - x + 6x + 2x = 2 + 1;

3x + 8x = 3;

3x + 8x - 3 = 0;

D = 8^2 - 4 * 3 * (-3) = 64 + 36 = 100

D = 100 = 10.

x1 = (-b + D)/2a = (-8 + 10)/2 * 3 = 2/6 = 1/3.

x2 = (-b - D)/2a = (-8 - 10)/2 * 3 = -18/6 = -3.

7) 2x + 11x + 34 = (x + 6);

2x + 11x + 34 = x + 12x + 36;

2x - x - 12x + 11x + 34 - 36 = 0;

x - x - 2 = 0;

D = -1^2 - 4 * 1 * (-2) = 1 + 8 = 9

D = 9 = 3.

x1 = (-b + D)/2a = (1 + 3)/2 = 4/2 = 2.

x2 = (-b - D)/2a = (1 - 3)/2 = -2/2 = -1.