To answer your question: Rewrite <span>81<span>x2</span></span> as <span><span>(<span>9x</span>)</span>2</span>.<span><span><span>(<span>9x</span>)</span>2</span><span>−49</span></span>Rewrite 49 as <span>72</span>.<span><span><span>(<span>9x</span>)</span>2</span><span>−<span>72</span></span></span> Both terms are perfect squares, factor using the difference of squares formula, <span><span><span>a2</span><span>−<span>b2</span></span></span>=<span><span>(<span>a+b</span>)</span><span>(<span>a<span>−b</span></span>)</span></span></span> where <span>a=<span>9x</span></span> and <span>b=7</span>.<span><span>(<span><span>9x</span>+7</span>)</span><span>(<span><span>9x</span><span>−7</span></span><span>)</span></span></span>
If she arrives by boat;
The distance she needs to row = Lake diameter
Distance = Lake diameter = 2 x Radius
Boat distance = 2 x 2 miles = 4 miles
So;
When moving on foot
The distance that needs to be moved D = Half of the circle circle
∴ D = π × Radius
The distance that needs to be moved D = π × 2 miles = 2π Miles
Arc length = Radius × θ
String length = radius x 2 x sin (θ / 2)
0 ≤ θ ≤ π, 0 ≤ sin (θ / 2) ≤ 1
Learn more here shore of a circular at
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Range is ] -20 , -10 [
both points are disclude according to the empty circle
