Question

find x

Answer 1

Is that... un , n and, n+20? o_O Very neat lines though. Looks like you doing a complimentary angles problem in which case this would help to remember:
\[Angles_{\triangle}=\angle_A+\angle_B+\angle_C=180^o\]
and
\[Line_{straight}=\angle_1+\angle_2=90^o \]

Answer 2

I don't see any x, and I am having a hard time understanding what's representing what. I'm sorry.