| 3x | + 6 = 15
| 3x | = 9
+) 3x = 9
=> x = 3
+) 3x = -9
=>x = -3
Vậy,..........
\(/3x/+6=15\)
\(/3x/=15-6\)
\(/3x/=9\)
\(\Rightarrow3x=9\) hoặc \(3x=-9\)
\(TH1:3x=9\) \(TH2:3x=-9\)
\(x=9:3\) \(x=-9:3\)
\(x=3\) \(x=-3\)
Vậy x = 3 hoặc x = -3
|3x| + 6 = 15
|3x| = 9
TH1: 3x = 9
x = 3
TH2: 3x = -9
x = -3
KL:...
Tìm x :
\(/3x/ + 6 = 15\)
\(/3x/ = 15 - 6\)
\(/3x/ = 9\)
\(=> 3x = 9 \) hoặc \(3x = -9\)
\(=> x = 3 \) hoặc \(3x = -3 \)