I have no idea what this is
![I have no idea what this is class=](https://us-static.z-dn.net/files/dca/641c905caa165a5140a43ffb22999fbb.png)
Answer:
23
Step-by-step explanation:
2x+14+x+7=90, 3x+21=90,3x=90-21. 3x=69, x=23