Assuming that the lines are parallel, both angles added together should equal 180°. -13x+39 is equal to the angle next to -4x+5, and those angles are supplementary, meaning that they add up to 180°.
So if we write out the equation, it should look like this: (-13x+39)+(-4x+5)=180. If you add like terms, then you should get -17x+44=180. Then get x alone, so subtract 44 from both sides. You should get -17x=136. Finally, divide both sides by -17 to get x alone, and you should get x= -8.
To get the angle measurements, just plug in -8 to both equations. First do -4(-8)+5 and get 37°, and for the other one do -13(-8)+39 to get 143°.
