10. 79 and x are vertical angles so they are equal to each other
11. 62 and x are complentary so they should add up to 90. Subtract 62 from 90 or setup the equation 62+x=90 to find your answer
12. 47 and x are supplementary angles so they add up to 180. Subtract 47 from 180 or setup the equation 47+x=180 to find your answer
13. 43+x must equal 90 because the two angles are complementary. After solving for that, subtract 90 from 180 to find y.
14. To find x subtract 88 from 180. x and z are vertical angles so they are equal, and 88 and y are vertical angles so they are also equal.
15. To find x subtract 90 from 180. To find y add 42 and 53 and subtract it from 180.