Решить 1. 1) x(2x+3)-8=2x^2 +11x 2) 7x- (3x-1)^2=10-(3x-1)(3x+1) 3)x+((x+10)/5)=((x-2)/3) -0.5)/3)+((x-2)/40=0.5 5)(3*((2/4)*-7)/12)=2.5x 2. 1)2x^2+9x+4=0 2)19x^2-76=0 /6)*/6)*x)+7=0 4) ((2*(1/3)**(1/2)*x=0 нужно за ранее огромное

1. 1) x(2x + 3) - 8 = 2x^2 + 11x

2x^2 + 3x - 8 = 2x^2 + 11x

-8 = 11x - 3x = 8x

x = -1

2) 7x - (3x-1)^2 = 10 - (3x-1)(3x+1)

7x - (9x^2 - 6x + 1) = 10 - (9x^2 - 1)

7x - 9x^2 + 6x - 1 = 10 - 9x^2 + 1

7x + 6x = 10 + 1 + 1

13x = 12

x = 12/13

3) x + (x + 10)/5 = (x - 2)/3

умножаем все на 15

15x + 3(x + 10) = 5(x - 2)

15x + 3x + 30 = 5x - 10

18x - 5x = -10 - 30

13x = -40

x = -40/13

4) (2x - 0,5)/3 + (x - 2)/40 = 0,5

умножаем все на 120

40(2x - 0,5) + 3(x - 2) = 60

80x - 20 + 3x - 6 = 60

83x = 60 + 20 + 3 = 86

x = 86/83

5) 3*(2/4)*x - (10x - 7)/12 = 2,5x

3x/2 - (10x - 7)/12 = 2,5x

умножаем все на 12

3x*6 - (10x - 7) = 2,5x*12

8x + 7 = 30x

7 = 30x - 8x = 22x

x = 7/22

2. 1) 2x^2 + 9x + 4 = 0

d = 9^2 - 4*2*4 = 81 - 32 = 49 = 7^2

x1 = (-9 - 7)/4 = -16/4 = -4; x2 = (-9 + 7)/4 = -2/4 = -1/2

2) 19x^2 - 76 = 0

x^2 = 76/19 = 4

x1 = -2; x2 = 2

3) (1/6)*x^2 - (13/6)*x + 7 = 0

умножаем все на 6

x^2 - 13x + 42 = 0

d = 13^2 - 4*1*42 = 169 - 168 = 1 = 1^2

x1 = (13 - 1)/2 = 12/2 = 6; x2 = (13 + 1)/2 = 14/2 = 7

4) (2/3)*x^2 - (3/2)*x = 0

умножаем все на 6

4x^2 - 9x = 0

x(4x - 9) = 0

x1 = 0; x2 = 9/4

Объяснение:

См. Фотки!!!