I need help with online schooling

Answer:
[tex]x=6\frac{2}{3}[/tex]
Step-by-step explanation:
Right angles always add up to 90°. You can tell it's a right-angle because of that square in the corner.
Anyway, the two angles should add up to 90°. So set up your equation:
70° + 3x = 90°
3x = 90 - 70
3x = 20
x = 20/3
[tex]x=6\frac{2}{3}[/tex]