Carilah himpunan kuadrat sempurna… a) x² + 2x – 15 = 0 b) x² + 4x – 12 = 0

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Carilah himpunan kuadrat sempurna…
a) x² + 2x – 15 = 0
b) x² + 4x – 12 = 0

Jawaban:

x1=–5 atau x2=3

Penjelasan dengan langkah-langkah:

{x}^{2} + 2x - 15 = 0 \ {x}^{2} + 2x = 15 \ {x}^{2} + 2(1)x + {(1)}^{2} = 15 + {(1)}^{2} \ {(x + 1)}^{2} = 16 \ x + 1 = pm sqrt{16} \ x = - 1 pm4

x_{1} = - 1 - 4 = - 5

x_{2} = - 1 + 4 = 3