For question 8:
the angle measurement of a straight line is 180, so:
180 - 50 = 130
y = 130
because the two lines are parallel, they have the same surrounding angle measurements.
x = 5
For question 9:
you can see a little box drawn in the angle, meaning it is a right angle. right angles measure 90 degrees.
90 - 20 = 70
c = 70
hope this helps! good luck