Respuesta :

I can answer this, but it is all based on assuming that both parts of that line are equal, so if you know otherwise then please don't use this answer.
3x + 5 = 5x - 7
- 3x
5 = 2x - 7
+ 7
12 = 2x
÷ 2
6 = x
So you get x as 6, I hope this helps!