|x^2+2x-5|=3

解

x^{2} + 2 x - 5 = 3

x = - 4 or x = - 1 - 3 or x = - 1 + 3 or x = 2

十進法表記

x = - 4, x = - 2.73205 \dots, x = 0.73205 \dots, x = 2

解答ステップ

x^{2} + 2 x - 5 = 3

絶対規則を適用する:

∣ u ∣ = a, a > 0

の場合は

u = a

u = - a

x^{2} + 2 x - 5 = - 3 or x^{2} + 2 x - 5 = 3

x^{2} + 2 x - 5 = - 3 or x^{2} + 2 x - 5 = 3

(x = - 1 - 3 or x = - 1 + 3) or (x = - 4 or x = 2)

x = - 4 or x = - 1 - 3 or x = - 1 + 3 or x = 2