Question

Help Me plez))))ggvp​

Answer 1

a.

3x² - 8x + 2 = 2x² - 4 - 3x

3x² - 2x² - 8x + 3x = -4 - 2

x² - 5x = -6

x² - 5x + 6 = 0

D = b² - 4×a×c

b = -5

a = 1

c = 6

D = 25 - 4 × 6

D = 25 - 24

D = 1

√D = 1

x1 = (-b - √D) ÷ 2a

x2 = (-b + √D) ÷ 2a

x1 = (5 - 1) ÷ 2 = 2

x2 = (5 + 1) ÷ 2 = 3

б.

(6 - 3х)(2+х) = 24 - х - 4х²

12 +6х -6х - 3х² = 24 - х - 4х²

-3х² + 4х² +х = 24 - 12

х² +х = 12

х² + х - 12 = 0

D = 1 - 4 × (-12)

D = 1 + 48

D = 49

√D = 7

x1 = (-1 - 7) ÷ 2 = -4

x2 = (-1 + 7) ÷ 2 = 3

в.

(х² + 6х - 55)(х² - 11х + 28) = 0

x² + 6x - 55 = 0 и х² - 11х + 28 = 0

х² + 6х - 55 = 0

D = 36 - 4 × (-55)

D = 256

√D = 16

x1 = (-6 - 16)÷2 = 11

x2 = (-6 +16) ÷ 2 = 5

x² - 11x + 28 = 0

D = 121 - 4 × 28

D = 9

√D = 3

x3 = (11 - 3)÷2 = 4

x4 = (11 + 3)÷2 = 7

ответ: x1 = 11, x2 = 5, x3 = 4, x4 = 7

г.

х² + 6|х| - 16 = 0

х² + 6х - 16 = 0 и х² - 6х - 16 = 0

х² + 6x - 16 = 0

D = 36 - 4 × (-16) = 36 + 64 = 100

√D = 10

условие: х ≥ 0

x1 = (-6 -10)÷2 = -8

x2 = (-6 + 10)÷2 = 2

х² - 6х - 16 = 0

D = 36 - 4 × (-16) = 36 + 64 = 100

√D = 10

условие: х ≤ 0

x1 = (6 - 10)÷2 = -2

x2 = (6 + 10)÷2 = 8

ответ: х1 = 2, х2 = -2