<p>How do you do this math question?</p>
<p>0 <= x =< y</p>
<p>(x+y)^2 - (x-y)^2 >= 25, what is the LEAST possible value of y</p>
<p>How do you approach this problem? Guess and check? Thank you for your support and help! :)</p>
<p>Ok. I worked this one out and think I have it...</p>
<p>What I did first was take the square root of both sides which leaves you with:</p>
<p>(x+y) - (x-y) >= 5 OR (x+y) - (x-y) >=(-5)</p>
<p>I first focused on the equation that is = 5 so...I reorganized to have x-x+y-(-y) which is the same as 0 + 2y or just 2y. So 2y = 5...y = 5/2. If you solve the equation = to -5 you will find that y = -5/2 BUT it has to be greater than 0, so 5/2 is the answer. </p>
<p>If you want to check your work, you can plug in Y=5/2 and solve for X which is complicated but you will end up with 10x = 25 so x also = 5/2. If you plug in both values, the equation works. Hope this helps and I apologize if its confusing. :)</p>
<p>I get it! I can't think like that under the time constraints though! :( Thank you though for enlightening me!</p>
<p>My teacher said you can't do what you did. :-</p>