Answer: I bolded the answers throughout the explanation.
Explanation:
Alright so we should first take note of where x is in relation to other angles.
x is on a straight line and so is 50 degrees.
Concept behind it: We know that both will ad up to 180 because a straight line is simply 180 degrees. It is the same reason why and "L" shape is always 90 degrees. So in other words if 90 degrees gets an L shape because the arm rotates counterclockwise, if it were to rotate another 90 degrees it would equal 180 degrees (because 90+90=180). If you just remember that a flat line is 180 degrees you should be good.
So now that it is established that 50+x=180 we just solve for x:
First, isolate x (the skipped to this step on your worksheet):
x=180-50
Simplify:
x=130
For the next one, we can once again assume that the flat line in total equals 180 degrees so lets set up an equation:
x+80=180
Isolate x:
x=180-80
Simplify:
x=100
Hope this helps. Post a comment if you need me to explain anything better :)