Question

81^2.5 × 9^4.5 ÷ 3^4.8 = 9^?

Options

• 7.1

• 9.4

• 4.7

• 4.5

Answer 1

7.1

Explanation:

81^2.5 × 9^4.5 ÷ 3^4.8 = 9^?

⇒ `(81^2.5xx 9^4.5)/3^4.8 = 9^?`

⇒ `((3^4)^2.5xx(3^2)^4.5)/3^4.8 = 9^?`

⇒ `(3^10xx3^9)/3^4.8 = 9^?`

⇒ 3^(10+9-4.8) = 9^?

⇒ 9^? = 3^14.2

⇒ (3)^2×? = 3^14.2

⇒ 2 × ? = 14.2

∴ ? = `14.2/2` = 7.1