The sum of squares is: (x)² + (x+1)² = 221 Expand second term: x² + x² + 2x + 1 = 221 Combine like terms: 2x² + 2x + 1 = 221 Subtract 221 from both sides to make quadratic form: 2x² + 2x - 220 = 0 Divide both sides by 2: x² + x - 110 = 0 Factor: (x + 11)(x - 10) = 0 x = -11 or x = 10