Răspuns:
x=(8/√18+6/√2)×√2/13
x=(8√18/18+6√2/2)×√2/13
x=(8×3√2+9×6√2)/18 × √2/13
x=(24√2+54√2)/18 × √2/13
x=78√2/18 × √2/13
x=78/13 × √2×√2/18
x=6 × √4/18
x=2/3
y=(5/√147-1/√3) ; √3/14
y=(5√147/147-√3/3) × 14/√3
y=(5√147-49√3)/147 × 14√3/3
y=(5×7√3-49√3)/21 × 2√3/3
y=(35√3-49√3)/21 × 2√3/3
y=-14√3/21 × 2√3/3
y=-2√3/3 × 2√3/3
y=-4×3 / 9
y=-4/3
N=|y-x|
N=|-4/3-2/3|
N=|-6/3|
N=|-2|
N=2 ∈ ℕ