1) 360°-18°-18°-3x°-3x°=0 6x=324° x=54° 2) 180°-49°-(x+3)°=0 (x+3)°=131° x=128° 3) 90°-42°-4x°=0 4x°=48° x=12° 4) 180°-86°-2x°=0 2x°=94° x=47° 5) 360°-117°-117°-3x°-3x°=0 6x=126° x=21° 6) 90°-66°-8x°=0 8x=24° x=3° 7) 180°-22°-(x-5)°=0 (x-5)°=158° x=163° 8) 90°-2x°-2x°=0 4x°=90° x=22.5° (i don't know if you can leave it like this or you have to write it in another way) 9) 90°-57°-3x°=0 3x°=33° x=11°
