Tìm số nguyên x: a) 46 – x = –21 + (–87) b) x – 96 = (443 – x) – 15 c) (–x + 281 +534) = 499 + (x – 48) d) –(754 + x) = (x – 12 – 741) – 23.
Câu hỏi:
Tìm số nguyên x:
a) 46 – x = –21 + (–87)
b) x – 96 = (443 – x) – 15
c) (–x + 281 +534) = 499 + (x – 48)
d) –(754 + x) = (x – 12 – 741) – 23.
Trả lời:
Lời giải
a) 46 – x = –21 + (–87)
⇔ 46 – x = –108
⇔ x = 46 – (–108)
⇔ x = 154
Vậy x = 154.
b) x – 96 = (443 – x) – 15
⇔ x – 96 = 443 – x – 15
⇔ x – 96 = 428 – x
⇔ x + x = 428 + 96
⇔ 2x = 524
⇔ x = 262
Vậy x = 262.
c) (–x + 281 +534) = 499 + (x – 48)
⇔ –x + 281 +534 = 499 + x – 48
⇔ –x + 815 = 451 + x
⇔ 815 – 451 = x + x
⇔ 364 = 2x
⇔ 182 = x
Vậy x = 182.
d) –(754 + x) = (x – 12 – 741) – 23
⇔ –754 – x = x – 12 – 741 – 23
⇔ –754 – x = x – 776
⇔ –754 + 776 = x + x
⇔ 22 = 2x
⇔ 11 = x
Vậy x = 11.
