Question 1 Report
Given that \(81\times 2^{2n-2} = K, find \sqrt{K}\)
Answer Details
To find K \sqrt{K} K given that 81 × 2 2 n − 2 = K 81 \times 2^{2n-2} = K 81×22n−2=K, we need to simplify the
expression step-by-step.
First,
rewrite 81 81 81 in terms of powers of 3 3 3: 81 = 3 4 81 = 3^4 81=34
So,
the given equation becomes: K = 3 4 × 2 2 n − 2 K = 3^4 \times 2^{2n-2} K=34×22n−2
Next,
we need to find K \sqrt{K} K: K = 3 4 × 2 2 n − 2 \sqrt{K} = \sqrt{3^4 \times 2^{2n-2}} K=34×22n−2
Using the property of square roots a × b = a × b \sqrt{a \times b} = \sqrt{a} \times \sqrt{b} a×b=a×b: K = 3 4 × 2 2 n − 2 \sqrt{K} = \sqrt{3^4} \times \sqrt{2^{2n-2}} K=34×22n−2
Since 3 4 = 3 2 = 9 \sqrt{3^4} = 3^2 = 9 34=32=9 and 2 2 n − 2 = 2 ( 2 n − 2 ) / 2 = 2 n − 1 \sqrt{2^{2n-2}} = 2^{(2n-2)/2} = 2^{n-1} 22n−2=2(2n−2)/2=2n−1: K = 9 × 2 n − 1 \sqrt{K} = 9 \times 2^{n-1} K=9×2n−1
Thus, the correct answer is: 9 × 2 n − 1 \boxed{9 \times 2^{n-1}} =