pigor: ..., np tak:
8|x−1|+(x−1)(x2+4)=0 ⇔
⇔ [x<1 i −8(x−1)+(x−1)(x
2+4)=0] lub [x ≥1 i 8(x−1)+(x−1)(x
2+4)=0] ⇔
⇔ [x<1 i (x−1)(x
2−4)=0] lub [x ≥1 i (x−1)(x
2+12)=0] ⇔
⇔ ([x<1 i x
2−4=0) lub (x ≥1 i x−1=0) ⇔ (x<1 i x=−2) lub (x ≥1 i x=1) ⇔
⇔
x=−2 lub
x=1 , czyli
x∊{−2,1} . ...