himpunan penyelesaian dari |5-1/3 x| = 8

Kuadratkan:
(5 - (1/3)x)² - 8² = 0
(5 - (1/3)x - 8)(5 - (1/3)x + 8) = 0
(- 3 - (1/3)x)(13 - (1/3)x) = 0
(1/3)x = - 3  atau  13 - (1/3)x = 0
x = - 9                              x = 39