Melengkapkan kuadrat sempurna -x²-x+6=0

-x²-x+6 = 0
_________ : (-1)
x² + x - 6 = 0
x² + x = 6
x² + x + (½)² = 6 + (½)²
(x+½)² = 24/4 + 1/4
(x+½)² = 25/4
x+½. = ± √25 / √4
x+½. = ± 5/2

X1 = -½ + 5/2 = 2
X2 = -½ - 5/2 = 3

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