14. 7ˣ = 343/4 va 7ʸ = 28 bo‘lsa, x + y ning qiymatini toping.

7ˣ · 7ʸ = (343/4) · 28 = 2401 = 7⁴. Demak, 7⁽ˣ⁺ʸ⁾ = 7⁴.

Javob: x + y = 4.