<p>I don't get how to do these 3 math problems.</p>
<p>If someone could explain them, that would be great!</p>
<p><a href="http://img4.imageshack.us/img4/3010/yxbv.png%5B/url%5D">http://img4.imageshack.us/img4/3010/yxbv.png</a> (#16)</p>
<p><a href="http://img854.imageshack.us/img854/7669/p3gi.png%5B/url%5D">http://img854.imageshack.us/img854/7669/p3gi.png</a> (#19,#20)</p>
<p>If the arc is 56, what is the value of angle O? </p>
<p>How much is angle O plus 2x? Could it be 180 degrees?</p>
<p>For twenty, complete the figure by extending the parallel line to y. You now have a rectangle with area 3y. This should be quite apparent from the answer choices. </p>
<p>Of course, the harder part is to define the area of the triangle. What can you say about the triangle with an angle of 45 degrees and one of 90? This should help identify the “extension” of the line as being the same as x. Now you have a triangle with area of 1/2 x^2. </p>
<p>Check if one answer matches the total of the triangle and the rectangle 3x.</p>
<p>For the first one, if the arc is 56 then the angle O is also 56. The triangle is isosceles so the other two angles are the same. 180-56= 124. 124 divided by 2 is 62 degrees. </p>
<p>Least i think thats how to do that one.</p>
<p>Here’s one way to do #19:</p>
<p>xy - x - y = 0</p>
<p>Add 1 to both sides and factor the LHS:</p>
<p>(x-1)(y-1) = 1</p>
<p>Since y > 2, y-1 > 1. Therefore x-1 is strictly between 0 and 1, or 1 < x < 2, D.</p>
<p>I actually think 20 is E. Draw a line separating the triangle from the rectangle. The area of the rectangle is clearly 3y. Both legs of the triangle of the triangle are x-3 since it’s a 45-45-90. So the area of the triangle is 1/2(x-3)^2.</p>
<p>It is indeed based on x-3 for the legs of the triangle. Figure was not clear on my phone.</p>
<h1>19 - graphing approach.</h1>
<p>Solve for y and graph or sketch
y = x/(x-1)
[Online</a> graphing calculator](<a href=“http://fooplot.com/plot/7josr6zbki]Online”>http://fooplot.com/plot/7josr6zbki)
All the values of x corresponding to the part of the graph above the line y=2 are in the interval (1; 2).</p>
