Carilah akar persamaan kuadrat berikut dengan rumus ABC
Penjelasan dengan langkah-langkah:
no. 1
x² + 2x - 15 = 0
a = 1 ; b = 2 ; c = -15
cari dulu diskriminannya (D)
D = b² - 4ac
D = 2² - 4(1)(-15)
D = 4 + 60
D = 64
x₁,₂ = (-b ± √D)/2a
x₁,₂ = (-2 ± √64)/2(1)
x₁,₂ = (-2 ± 8)/2
x₁,₂ = (-1 ± 4)
x₁ = -1 + 4 = 3
x₂ = - 1 - 4 = -5
jadi akar²nya x = 3 dan x = -5
no. 2
2x² - x - 10 = 0
a = 2 ; b = -1 ; c = -10
cari dulu diskriminannya (D)
D = b² - 4ac
D = (-1)² - 4(2)(-10)
D = 1 + 80
D = 81
x₁,₂ = (-b ± √D)/2a
x₁,₂ = (-(-1) ± √81)/2(2)
x₁,₂ = (1 ± 9)/4
x₁ = (1 + 9)/4 = 10/4 = 5/2
x₂ = (1 - 9)/4 = -8/4 = -2
jadi akar²nya x = 5/2 dan x = -2
" maaf kalau salah "
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