3x – 47.2 + x = - 29 + (-9)
3x – 47.2 + x = -38
3x – 94 + x = -38
3x – 94 = -38 - x
3x + x = -38 + 94
4x = 56
x = 56 : 4
x = 14
Vậy x = 14
\(3x-47.2+x=-29+\left(-9\right)\\ \Rightarrow4x-94=-38\\ \Rightarrow4x=-38+94\\ \Rightarrow4x=56\\ \Rightarrow x=56:4\\ \Rightarrow x=14\)