<p>Yes mic, lol that’s exactly what I did:) thanks</p>
<p>@Jor26029 Yes, that is equal to 0.</p>
<p>@Jor26029 Yes, just plug it into your calculator. I just opened up the calculator app on my computer and it took me about 5 seconds to do.</p>
<p>Never mind, I completely misread the question. There are actually 10 positive digits. The only negative one is the first term, -1. You’re subtracting positive numbers, which causes you to decrease in value. If you subtracted negative numbers, it would be the same as adding a positive number.</p>
<p>Can someone please explain me how to solve this?
<a href=“http://i.imgur.com/xBm4EhS.jpg”>http://i.imgur.com/xBm4EhS.jpg</a></p>
<p>@thezealot Ya, if you could get your link to work.</p>
<p>Replace the asterisks with imgur.</p>
<p>@thezealot The area of ABCD is 2x^2 + 6x and the area of RSTU is 3x^2 + 2x. It says these areas are equals so 2x^2 + 6x = 3x^2 + 2x --> x^2 - 4x = 0 --> x(x-4) = 0. Since x is positive, x = 4. The area of the shaded region is 3x = 12.</p>
<p>@MITer94 thanks.</p>
<p>Here is another one:</p>
<ol>
<li>Which of the following is the equation of a line in the xy-plane that is perpendicular to the line with equation x = 2 ?</li>
</ol>
<p>A. x = -1/2
B. x = -2
C. y=3
D. y= -1/2x
E. y = -2x</p>
<p>Can the answer be determined without looking at the answer choices?</p>
<p>Every horizontal line is perpendicular to every vertical line. </p>
<p>Horizontal lines have equation y = b, for some real number b.</p>
<p>Vertical lines have equation x = a, for some real number a.</p>
<p>So x = a and y = b are equations of perpendicular lines, no matter what real numbers a and b are.</p>
<p>Yeah, C is correct.</p>
<p>11, 2, x, 7, 12
The average (arithmetic mean) of the five numbers above is the same as the median of these numbers. What is one possible value of x? (I’d appreciate if you can give a quick way to solve this type of problem, and also explain why a non-integer number cannot be a correct answer)</p>
<p>Hey there AverageFail. First thing you should, for simplicity’s sake, line them up accordingly.
2,7,x,11,12. (Let’s assume x is the median)
Now, try to find out the average as you would normally do.</p>
<p>(2+7+x+11+12)/5 = … Since in the question it says the median is the same as the average, you can conclude
(2+7+x+11+12)/5 = x
-Multiply both sides by 5.
(2+7+x+11+12) = 5x
-Substract x from both sides:
2+7+11+12 = 4x.
-And solve!
32 = 4x —> x = 8 </p>
<p>@AverageFail as to why x must be an integer:</p>
<p>Suppose x were not an integer. Then the mean is (32+x)/5 which cannot possibly be an integer, so the median must be x. Then (32+x)/5 = x --> x = 8, which is an integer, contradiction! (however this does lead to a correct answer, since 8 is the median of {2,7,8,11,12}).</p>
<p>Yep, well so can 23…</p>
<p>If you want to find all x, the best way is to just do casework on what the median is – there can only be three possible values for the median, 7, x, 11.</p>
<p>. … … —|-----o----|----o----|----|----|----
0.03x 0.04x
On the number line above, the coordinates of two points are shown. If the distance between the points is 2, what is the value of x?
Edit: This looks horrible, sorry. The points are 2 spaces away from one another. There is one point between them, and they’re evenly spaced. the first point has a value of 0.03x, the second has a value of 0.04x.</p>
<p>Hint: What is the distance between the two points (in terms of x)?</p>
<p>Can someone help me with this:
P.518 Blue Book #14</p>
<p>T^2-k^2<6
T+k>4</p>
<p>@Jor26029 Thanks.</p>
<p>@7alman Declare x = a-3, therefore a = x+3. So when you change F(a-3) into F(x), change the a into (x+3)
F(x) = (x+3)^2 - 7(x+3) + 12
=x^2 + 6x + 9 - 7x - 21 +12
=x^2 - x</p>