|2x+5|+|2x-6|=8

解答

∣ 2 x + 5 ∣ + ∣ 2 x - 6 ∣ = 8

x \in R 无解

求解步骤

∣ 2 x + 5 ∣ + ∣ 2 x - 6 ∣ = 8

找到正负区间

x < - \frac{5}{2}, - \frac{5}{2} \leq x < 3, x \geq 3

对每个区间解不等式

x \in R 无解

(- x^{2} + x - 1)^{3} + x^{2} - x + 1 = 0

∣ x - 1 ∣ ∣ x + 5 ∣ = 7

x^{2} + 6 x + 6 = x^{2} + 4 x + 9 + ∣ 2 x - 3 ∣

x^{2} + 3 x + 2 + x + 1 = 0

x^{2} - 4 x + 2 = \frac{( 5 x - 4 )}{3}