9a) DOA and BOC are verticals angles so they have the same measure. So 117=30+40+a. So to solve for a you need to solve the equation 117-30-40=a. The answer is 47.
9b) AOD and DOB are supplementary so they equal 180 degrees. So the equation you would need to solve for b is 7b+3b=180, 10b=180, b=18. 7b is verticals angles with angle c so the equation to find that would be 7b=c. We know b is 18 so we substitute. 7(18)=c, 47=c.
10a) for of y=x+z they are on a straight line. Meaning it is 180 degrees. So for y to be equal to x+z they would need to be half y measure because y will be double there’s. So this is kinda hard to explain without a picture but y=90 x=45 z=45 hence 90=45+45.
10b) since they all equal each other just divide 180/3=60 and there is your andwernumber