Leah is 24 and her cousin is 12. Since 24 is double of 12, thats your answer and it makes the most sense.
Step-by-step explanation:
xy + 10 = 0. => y = -10/x.
2x + 3y = 7. => 3y = -2x + 7, y = -2/3 x + 7/3.
When -10/x = -2/3 x + 7/3,
-10 = -2/3 x² + 7/3 x, 2/3 x² - 7/3 x - 10 = 0.
=> 2x² - 7x - 30 = 0
=> (2x + 5)(x - 6) = 0
=> x = -2.5 or x = 6.
dy/dx = d/dx [-10/x] = 10/x².
When x = -2.5, dy/dx = 10 / (-2.5)² = 1.6.
When x = 6, dy/dx = 10 / (6)² = 5/18.
Hence the gradients at the points are 1.6 and 5/18.
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>
Answer:
x + y are either 2 or 4
Step-by-step explanation:
conclusion x + y = 2 OR 4
