5x-6x+1=0 4x-36x+77=0 x-22x-23=0 5x+(2x+1)(x-3)=0 (2x+3)(3x+1)=11x+30

1) 5х^2 - 6х + 1 = 0.

D = b^2 - 4ac = 6^2 - 4 * 5 * 1 = 36 - 20 = 16.

x1 = (-b + D)/2a = (6 + 4)/10 = 10/10 = 1.

x2 = (-b - D)/2a = (6 - 4)/10 = 2/10 = 1/5.

2) 4x^2 - 36x + 77 = 0.

D = (-36)^2 - 4 * 4 * 77 = 1296 - 1232 = 64.

x1 = (36 + 8)/8 = 44/8 = 5 4/8 = 5 1/2.

x2 = (36 - 8)/8 = 28/8 = 3 4/8 = 3 1/2.

3) x^2 - 22x - 23 = 0.

D = 484 + 4 * 1 * 23 = 576.

x1 = (22 + 24)/2 = 23.

x2 = (22 - 24)/2 = -1.

4) 5x + (2x + 1) * (x - 3) = 0;

5x + 2x^2 - 6x + x - 3 = 0;

2x^2 - 3 = 0;

2x^2 = 3;

x^2 = 3 : 2;

x^2 = 1,5;

x = 1,5.

5) (2x + 3) * (3x + 1) = 11x + 30;

6x^2 + 2x + 9x + 3 - 11x - 30 = 0;

6x^2 + 11x - 11x - 27 = 0;

6x^2 = 27;

x^2 = 27/6;

x^2 = 9/2;

x = 9/2;

x = 3/2;

x = 32/2.