Help w/2 Math Questions

<p>Hi! ^_^ I'm kind of having trouble figuring out how to get the answers for 2 math questions from a PR Math book. Could you explain how they got it?</p>

<p>1) If x is a positive even integer and y is a negative odd integer, then which of the following must be a positive odd integer?</p>

<p>[A] x^3y^2
<a href="xy+">B</a>^2
[C] xy^2 - 1
[D] x+y
[E] x+y/xy</p>

<p>The answer I put down was A. However, in the book it stated that the answer is C. O_o; The explanation the book gave me was kind of confusing.</p>

<p>2)Nicoletta deposits $150.00 in her savings account. If this deposit represents a 12% increase in Nicoletta's savings, then how much does her savings account contain after the deposit?</p>


<p>The correct answer is C. Still have no clue how they got the answer.</p>

<p>^__^ Thanks for viewing and replying!</p>

<p>For the 1st one, just plug in numbers of your choice for x and y, and then try them out.</p>

<p>FOr the 2nd one</p>

<p>150 = .12x.... understand that?</p>

<p>well then, x = 1250</p>

<p>1250 + 150 = 1400.</p>

<p>rick he is talking bout integers...e might not be an integer or odd</p>

<p>any number ^2 becomes positive and even and -1 to make it odd</p>

<p>if I'm not mistaken the answer to question 1 looks like E, since xy must be negative (x is positive, y is negative).</p>

<p>for number 2, a 150 dollar increase represents a 12% increase, therefore 12/100 = 150/x x = 1250.
1250 is the amount she has b4 the deposit, then she deposited another 150, 1250+150 = 1400.</p>

<p>for number 1a, odd * odd = odd, even * odd = even.</p>

<p>Thanks you guys! I understood the answer to the second question except for the first one. Because I think it should either be A or C. It both worked. TT; Maybe PR put two answers down. Blah...</p>

<p>no...a is even..won't work</p>

<p>a) even^3 = even; odd^2 = odd
even * odd = even</p>

<p>b) can't really tell what it says, but I'm assuming its xy + some even number.
even * odd (xy) = even
even + even (xy + ?) = even
even^2 (xy + ?)^2 = even</p>

<p>c) odd^2 (y^2) = odd, positive
even * odd (xy^2) = even, positive
even - 1 (xy^2 - 1) = odd, positive</p>

<p>d) even + odd = odd, but not necessarily positive</p>

<p>e) If this is x + y/(xy), then that simplifies to x + 1/x, which won't be an integer unless x = 1, in which case, x + 1/x = 2, which is even.
If this is (x+y) / (xy), then this simplifies to 1/x + 1/y, which won't be a positive integer (only integer it could be is zero)</p>

<p>nicely explained and same answer</p>