Tìm x: (–12) – (13 – x) = –15 – (–17).
Tìm x: (–12) – (13 – x) = –15 – (–17).
(–12) – (13 – x) = –15 – (–17)
(–12) – (13 – x) = –15 + 17
(–12) – (13 – x) = 2
–13 – x = 2 + 12
–13 – x = 14
x =14 – 13
x = 1.