Tìm x biết: -125 + 2(5 - x) = -5
Tìm x biết: –125 + 2(5 – x) = –5.
–125 + 2(5 – x) = –5
⇔ 2(5 – x) = –5 – (–125) = –5 + 125 = 120
⇔ 5 – x = 120 : 2
⇔ 5 –x = 60
⇔ x = 5 – 60
⇔ x = –55
Vậy x = –55.