Question

Помогите с алгеброй пжпжпжпжжп

Answer 1

Ответ:

Объяснение:

1)

2х² - 9x + 4=0

D = 9² - 4 * 2*  4 = 81 - 32 = 49

√D = √49 = 7

х1= (9 + 7)/2*2 = 4

х2 = (9 - 7)/2*2= 1/2  

2)

3х² + 8x - 3 =0

D = 8² - 4 * 3 *( - 3) = 64 + 36 = 100

√D = √100 = 10

х1= (-8 + 10)/2*3 = -1/3

х2 = (-8 - 10)/2*3= - 3

3)

х(х + 2) = 3

х² + 2х - 3 =0

D = 2² - 4 *( - 3) = 4 + 12= 16

√D = √16 = 4

х1= (-2 + 4)/2 = 1

х2 = (-2 - 4)/2 = - 3

4)

3х² + 9 = 12х - х²

4х² - 12х + 9 = 0

D = 12² - 4 * 4 * 9 = 144 - 144 = 0

х1= (12 + 0)/2* 4= 3/2

5)

8/(х-2) = 4/(х - 5)

8(х - 5) = 4(х - 2)

8х - 40 = 4х - 8

8х - 4х = - 8 + 40

4х = 32

х = 32 : 4

х = 8