Answer:
x = 17
Step-by-step explanation:
Combine like terms first:
x + 3x + 4 = 72 --> 4x + 4 = 72
Isolate the variable by subtracting 4 from both sides so you get
4x = 72 - 4
4x = 68
Divide both sides by 4 to get
x = 68/4