Mohon Bantuan Nya Kak, Makasih

Mapel : Matematika
Kelas : VIII SMP
Bab : Persamaan Kuadrat

Pembahasan :
6.

2x² - x - 6 = 0

Menurut Teorema Vietta
a + β = -b/a
a + β = 1/2

aβ = c/a
aβ = -3

Maka...
a/β + β/a
= (a + β)/aβ
= (1/2)/(-3)
= - 1/6

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7.

2x² - x - 5 = 0

Menurut Teorema Vietta
a + β = -b/a
a + β = 1/2

aβ = c/a
aβ = -5/2

Maka...
x² - (X1 + X2)x + (X1 . X2) = 0
x² - [4a + 4β)x + (4a . 4β) = 0
x² - [4(a + β)]x + [16aβ] = 0
x² - [4(1/2)]x + [16(-5/2)] = 0
x² - 2x - 40 = 0