Tìm x \( \in \) Z, cho biết :
\(\eqalign{ & a)\;x + 27 = 44 + \left( { - 7} \right) \cr & b)\;x - 22 = 12 + \left( { - 4} \right) \cr & c)\;\left| x \right| + 25 = \left| { - 37} \right| - 12 \cr & d)\;\left| x \right| - 26 = \left| { - 27} \right| - 23. \cr} \)
a) \(x + 27 = 44 + (-7)\)
\( x + 27 = 37\)
\(x = 37-27\)
\(x = 10\)
b) \(x - 22 = 12 + (-4)\)
\(x - 22 = 8\)
\(x = 8 + 22\)
\(x = 30\)
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c) \(|x| + 25 = |37| -12\)
\(|x| + 25 = 37 -12\)
\(|x| + 25 = 25\)
\(|x| = 25 -25\)
\(|x| = 0\)
d) \(|x| - 26 = |27| -23\)
\(|x| - 26 = 27 -23\)
\(|x| - 26 = 4\)
\(|x| = 4 + 26\)
\(|x| = 30.\)
Vậy \(x = 30\) hoặc \(x =-30\)