<p>This is from 11 practice test for the new SAT 2008 edition</p>
<p>Page 138 question 17…</p>
<p>If (C+1)*2 = -b Which of the following statements must be true?</p>
<li>C>0</li>
<li>C=0
3 C<0</li>
</ol>
<p>A) None
B) 1 only
C) 3 only
D)1 and 2 only
E) 1,2 and 3</p>
<p>PR says its E but i got A…Because anything squared should be more than a negative like if i chose
5+1= 6… squared 36 not a negative number and same thing with everything else…Am I missing something doing something wrong??</p>
<p>yes in fact you are really missing sth important
you say : anything squared should be more than a negative like if i chose
that's true but you are not asked to draw a conclusion for (c+1)^2 which is > or = to zero , but for c that can be positive ex : (7+1)^2 = - (-64)
negative ex : ( -2+1)^2 = - (-1)
and zero (0+1) ^ 2 = - (-1)
i hope that was a good explanation to this problem :D</p>
<p>is that the entire setup? is there any reason that -b can't be positive (that is, that the value of b can't be negative)? also, it's impossible that c MUST be greater than, less than, and equal to zero--no number is greater than, less than, and equal to zero.</p>
<p>@ yosei : i think E-A-S-E used * to denote the exponent since 2 comes after c+1 ( if multiplication 2 would come before c+1 )
@ xitammarg : there is a well known rule in elementary algebra that says : no square is negative. this means that (c+1)^2 isn't negative. in other terms -b is not negative (since (c+1)^2 = -b) . and yes , -b can be positive even though it contains a minus sign ( for example - - 7 = 7 is positive ) . However we are not asked for b , we are asked for c . as i explained c can take positive ,zero and negative values but not all at the same time :)
if anything , don't hesitate to ask</p>
<p>I still don't get it..I see that we are beaning asked what C is and after the equation they say that B should be a negative but none of them gives negative...I still dont understand it..</p>
<p>right, but what i'm saying is that the problem, as written, has (at least) two flaws. first, the OP used the * sign but then referred to squaring an expression, so we can't be sure which one he means--whether he misunderstood the question, or whether he mistyped it.</p>
<p>second, and more importantly, -b can be any number at all unless we're given some information about it. this would mean that the question asks us to find a number c such c+1 [times 2 or squared] equals any number. that means c can be any number.</p>
<p>if c can be any number, then saying it MUST be true that c < 0, c = 0, and c > 0 is nonsensical, because there is no possible value for c that could satisfy all of those conditions as the word MUST would require.</p>
<p>if the question said "which of the following MAY be true?" then (e) would be correct. if it asks which MUST be true, then (a) would be correct, because none of the conditions MUST be true: if c = 7, which is possible, then it isn't true that c < 0 and c = 0; if c = -7, then it isn't true that c > 0.</p>
<p>that's why i wanted to clarify that the question was provided exactly as written, because the version in the original post doesn't make any sense.</p>
<p>^exactly my thoughts</p>
<p>Well, first of all we have no idea what C and b are. If b is negative, then -b is positive, and the whole question changes.</p>