|x^2-12x+31|=4

解

x^{2} - 12 x + 31 = 4

x = 3 or x = 5 or x = 7 or x = 9

解答ステップ

x^{2} - 12 x + 31 = 4

絶対規則を適用する:

∣ u ∣ = a, a > 0

の場合は

u = a

u = - a

x^{2} - 12 x + 31 = - 4 or x^{2} - 12 x + 31 = 4

x^{2} - 12 x + 31 = - 4 or x^{2} - 12 x + 31 = 4

(x = 5 or x = 7) or (x = 3 or x = 9)

x = 3 or x = 5 or x = 7 or x = 9