Himpunan penyelesaian dari X² + X – 7 = 0 adalah​

x² + x – 7 = 0

x² + x = 7

x² + x + (½)² = 7 + ½²

(x + ½)² = 7 + ¼

(x + ½) = ±√29/4

(x + ½) = ±√29/2

x + ½ = √29/2

x = √29 – 1 / 2

x + ½ = -√29 / 2

x = -√29 – 1 / 2