Well, the first one is 2/40=1/20. The 2nd one is 1/39. You multiply these to get 1/780.
I found the value of x to be 6 by adding the two equations together and setting them equal to 180.
2x^2+3x-5+x^2+11x-7=180
When you solve for x you get x=6
Then you plug 6 in for x in each angle. The first angle is 85 and the second is 95.
4. 3x-27 = 90
3x = 63
x = 21
5. 2x+30 = 60
2x = 30
x = 15