Answer:
1
Explanation:
Let x represent the number. The given relation is ...
x² +(x+3)² = 17
2x² +6x +9 = 17 . . . . simplify
x² +3x -4 = 0 . . . . . . subtract 17 and divide by 2
(x +4)(x -1) = 0 . . . . . factor
The solutions make these factors zero: -4 and +1. The positive solution is 1.
The number is 1.