11. 2ˣ = 64/9 va 2ʸ = 9 bo‘lsa, x + y ning qiymatini toping.

Darajalarni ko‘paytiramiz: 2ˣ · 2ʸ = (64/9) · 9 = 64 = 2⁶. Demak, 2⁽ˣ⁺ʸ⁾ = 2⁶, shuning uchun x + y = 6.

Javob: 6.