Answer:
The | signs are absolute value signs. Absolute value just makes a negative value turn positive, because technically there is no negative value. For example |-x+5| turns into x+5. If it's already positive, it stays the same. So basically, they're just acting as parenthesis right now. Just distribute the 3 and get 3x+15=7. subtract 17 and get 3x=-8. Divide both sides by three, and you should get x= -8/3. But wait, there's more. Since this is an absolute value equation, there should be more than one answer. Simply make the number on the other side negative. 3x+15=-7. subtract 15 and get -22. Keep going and your answer should be -22/3.
So in conclusion, your two answers are -8/3 and -22/3.