Correct Option: A

81^2.5 X 9^4.5 ÷ 3^4.8 = 9^?
⇒ 81^2.5 x 9^4.5 ÷ 3^4.8 = 9^?
Apply the law of Fractional Exponents and Laws of Exponents
(a^m)ⁿ = a^{m x n} ----------------1
(a^m) x (aⁿ) = a^{m + n}-------------2
a^m ÷ aⁿ = a^{m ? n}----------------3
and if p^X = p^Y then X will be equal to Y. means X = Y;----------------4

Apply Law 1
⇒ (9²)^2.5 x 9^4.5 ÷ 3^{2 x 2.4} = 9^?
⇒ 9⁵ x 9^4.5 ÷ 9^2.4 = 9^?
Apply law 2 and 3,
⇒ 9^{(5 + 4.5 - 2.4)} = 9^?
⇒ 9^? = 9^7.1
Apply the Law 4
∴ ? = 7.1