Answer:
7
Step-by-step explanation:
It’s a right angle, so you can add the two expressions togther to get 90, then isolate x.
(8r-6)+(5r+5)=90
13r-1=90 (combine like terms)
13r-1+1=90+1 (add 1, addition property of equality)
13r=91
13r/13=91/13
r=7
