Tolong ya bsk di kumpul

2a. 180-69=111 2c. 100,8
2b. 180-117=63 2d. 27,6

4a. 5x-10+90+7x-20=180
12x+60=180
12x=120
x=10
4b. AOB=5. 10-10=40°
4c. COD=7. 10-20=50°