Question 78280
x^2+(x+1)^2=85
x^2+x^2+2x+1=85
2x^2+2x+2-84=0
x^2+x-42=0
(x+7)(x-6)=0
x+7=0
x=-7 
x-6=0
x=6 answer.
6^2+(6+1)^2=84
36+49=85
85=85