Need help with # 3 and 6!

Answer: 3 is x=50
Need more info for 6
Step-by-step explanation:
3) 3x+10=4x-40
50=x
6) 5 is 90 degrees, 3+1=90 degrees, and 4+2=90 degrees.
It is not clear what we are supposed to be solving, so I think there is some needed information cropped out of the photo. Hopefully my explanation of what equals what helps you solve it!