<p>Can anyone explain how to get these answers?</p>
<p><a href="http://i.imgur.com/Ii39f.jpg%5B/url%5D">http://i.imgur.com/Ii39f.jpg</a>
Answer is C.</p>
<p><a href="http://i.imgur.com/h57kh.jpg%5B/url%5D">http://i.imgur.com/h57kh.jpg</a>
Answer is also C. I got this one right, but I want to know if there's a quicker way of doing it.</p>
<p><a href="http://i.imgur.com/qjicY.jpg%5B/url%5D">http://i.imgur.com/qjicY.jpg</a>
Answer is E.</p>
<p>Thanks!</p>
<p>For the 2nd one, what i did was just make up numbers that fits the requirements of the question. So I said p= 10 and r= 20, thus pr=200. Divide 200 by 7 and you get a remainder of 4. (C)</p>
<p>For the 3rd one, you should know the distance formula, d=SQRT((x1-x2)+(y1-y2)
You’re given the distance, 13, and two of the points, (2,r) and (14,2)
From here you can set up the equation as follows: 13= SQRT((14-2)+(2-r))
Then square both sides to make it easier to look at: 169=(12)^2+(2-r)
169=144+(2-r)–> bring the 144 to the other side —> 25= 2-r—> solve for r and you get -3, (E)</p>
<p>Thanks for the help so far!</p>
<h1>2: Translate the english into math:</h1>
<p>p = 3 (mod 7)
r = 6 (mod 7)
pr = ? (mod 7)</p>
<p>Obviously just multiply the equations:</p>
<p>pr = 18 (mod 7)
pr = 4 (mod 7)</p>
<p>[4]===> (C)</p>
<p>79 80’s
81 81’s
82 …
83 …
84 84’s</p>
<p>Sum up: 79+81+82+83+84 = 409 ===> C</p>
<p>For the second one just choose values for p and r, say p=10, r=13. Then pr=130, and 7 goes into 130 18 times with a remainder of 4.</p>
<p>Notes: (1) I got p by adding 7 and 3, and I got r by adding 7 and 6.</p>
<p>(2) p=3 and q=6 are even better choices (7 goes into 3 zero times with a remainder of 3, etc.) In this case pq=18, and 18 divided by 7 is 2R4. Since this is conceptually a bit more confusing I usually explain the problem with the first numbers I chose initially.</p>
