<p>x=8
8,9,17,20,29</p>
<p>x, 9, x+9, 2x+4, x^2 - 35
My method. In a question like this, it seems wisest to look for concrete value(s). In this particular question we have 9. Since we know that values go from least on the left to greatest on the right, we know the 9>x ect. The next step for me was to look at the last "value"(it happens to have a number that makes sense; -35). Its plain to see that 9<x^2-35 -=""> X^2>44. This means that x must be greater than 6(now clearly, there are many terms in between 9 and the greatest term, implying that its not very likely that x=7. Further examination, shows more information. Looking at the last two terms X^2> 2x +39, the new limit of X>7 is uncovered. Then plug in values.</x^2-35></p>
<p>^^Great observation about x^2 -35 > 9 -> x>=7.
The next easy step would be using using "we know the 9>x " -> x=7 or x=8.
Obviously, x+9>9 for positive numbers, so compare x+9 and 2x+4 for x=7. It does not work.
There is no need to check 8, because, according to the question, the right number does exist.
x=8.</p>
<p>Thanks you guys :) </p>
<p>I'll have a new question shortly :)</p>
<p>x^2-35 shouldn't be negative. then it is implied that x>6, 7, 8.
3 attempts till the correct one.</p>
<p>Alright, new question. But first a quick note: This problem uses a diamond symbol that I don't know how to type, so I'm just going to use "@" in place of it.</p>
<p>For all numbers a and b, let the operation @ be defined by a @ b = b^2 + ab. What is the value of (1 @ 2) @ 3?</p>
<p>First calculate 1 @ 2:</p>
<p>1 @ 2
2^2 + 1(2)
4 + 2
6</p>
<p>Then calculate [1 @ 2] @ 3:</p>
<p>[1 @ 2] @ 3
6 @ 3
6^2 + 6(3)
36 + 18
54</p>
<p>Ans: 54</p>
<p>^ That answer isn't right according to the answer sheet, which says that the correct answer is 27.</p>
<p>CORRECTION</p>
<p>My method was correct, I believe. I made an error while plugging in the numbers. Here is the revised version (Sorry for the trouble):</p>
<p>First calculate 1 @ 2:</p>
<p>1 @ 2
2^2 + 1(2)
4 + 2
6</p>
<p>Then calculate [1 @ 2] @ 3:</p>
<p>[1 @ 2] @ 3
6 @ 3
3^2 + 6(3)
9 + 18
27</p>
<p>Ans: 27</p>
<p>Yeah, no problem, don't worry about the mistake. Thank you :)</p>
<p>i was confused on those problems at first. now i got used to it, which means practicing is really important. kk</p>
<p>I have another question on a problem with a diagram, so I drew it up on paint.</p>
<p>is the answer 1/4?</p>
<p>i mean 1/8*</p>
<p>Connect the middle point of PT with Q and S.</p>
<p>i desperately need help w/ the math section</p>
<p>what confuses me the most is the questions that ask what is a in terms of b o and ones that give u many variables and ask you to find the value of one of them
for example (( from mcgraw hill 2nd edition book [pg 324)</p>
<p>for all positive values of m and n, if 3x/m-nx=2 then x =</p>
<p>and also</p>
<p>if 2x+z=2y and 2x+2y+z=20, what is the value of y?
a)5
b)8
c)10
d)15
e) cannot be determined</p>
<p>Alright let's look at these carefully. </p>
<p>For the first one, the trick is to ISOLATE x. So we have to do:</p>
<p>3x/(m-nx) = 2
3x = 2m - 2nx</p>
<p>See how that works? I just brought the bottom on the other side through multiplication. Now we should get all the TERMS with x on one side</p>
<p>3x = 2m - 2nx
3x + 2nx = 2m</p>
<p>We have a problem. All the terms with x are on the left side. However, we are finished with moving stuff around. But wait a minute...BOTH terms on the left have X in them. Can we factor X out? That would isolate it, wouldn't it?</p>
<p>3x + 2nx = 2m
x(3 + 2n) = 2m</p>
<p>Now we can easily isolate X:</p>
<p>x(3 + 2n) = 2m
x = 2m/(3 +2n)</p>
<p>For the second one. This one seems tedious, doesn't it? Man...how long would it take to solve so many equations :( Oh well, let's give it a shot!</p>
<p>We have three unknowns (x, y, z) and we have three equations. Or do we? Where is the third equation? It's not even given! We can't find a numerical value for Y! Thus, E would be the answer.</p>
<p>Hoopsplaya - the correct answer is 3/4</p>
<p>and thanks hoopsplaya and gcf for your responses! :)</p>
<p>crap i screwed up big time</p>
<p>confused!!! is it 3x/m-nx=2 or 3x/(m-nx) = 2?????</p>