Question

Ada yang bisa bantu???​

Answer 1

Penjelasan dengan langkah-langkah:

1] x² - 20 = 8x

x² - 8x - 20 = 0

a = 1; b = -8; c = -20

(x1)² + (x2)²

= (x1 + x2)² - 2 . x1 . x2

= (-b/a)² - 2 . c/a

= (- (-8/1))² - 2 . (-20/1)

= 64 + 40

= 104

2] 1/x - 1/(x + 3) = 3/10

(x + 3 - x)/(x . (x + 3)) = 3/10

3/(x² + 3x) = 3/10

3 : 3 = 1

1/(x² + 3x) = 1/10

x² + 3x = 10

x² + 3x - 10 = 0

(x + 5) . (x - 2) = 0

x - 2 = 0

x = 2

x + 5 = 0

x = -5

x1 > x2

2 > -5

x1 - x2

= 2 - (-5)

= 2 + 5

= 7

Kode Kategorisasi : 9.2.9

Kelas 9

Pelajaran 2 - Matematika

Bab 9 - Persamaan Kuadrat