Answer:
x = 5
Explanation:
You want to find x such that ...
x^2 +(x +1)^2 = 61
2x^2 +2x -60 = 0 . . . . . simplify, subtract 61
x^2 +x -30 = 0 . . . . . . . divide by 2
(x +6)(x -5) = 0 . . . . . . . . factor; solutions will make the factors be zero.
The relevant solution is x = 5.