Question 880682
They are a linear pair. So they add to 180 degrees



{{{(5x+20)+(5x+30)=180}}}



{{{5x+20+5x+30=180}}}



{{{10x+50=180}}}



{{{10x=180-50}}}



{{{10x=130}}}



{{{x=130/10}}}



{{{x=13}}}