Help With Some MATH Problems

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1

<p>Hello all, could you please explain some of these problems for me.</p>

<p>Free Response Questions:</p>

<p>1) tx + 12y = -3</p>

<p>The Equation above is the equation of a line in the xy-plane, and t is a constant. If the slople of the line is -10, what is the value of t?</p>

<p>Answer: 120 (Not sure how to arrive at this answer)</p>

<p>2) The number n is a 2 digit number. When n is divided by 10, the remainder is 9, and when n is divided by 9, the remander is 8. What is the value of n?</p>

<p>Answer: 89 (answer makes sense to me, but can you explain to me a quicker way to solve this other than plugging values in?)</p>

<p>Thank You!</p>

2

<p>For 1), you just want to get the equation in y=mx+b form (or maybe point slope).</p>

<p>Divide the whole thing by 12 and you get (1/12)tx+y=meaningless number (3/12). Then subtract away the x and you get y=-(1/12)tx+b. Now solve: -1/12t=-10 and you get 120.</p>

<p>Should take about 15 seconds, imo, then five or ten to check.</p>

<p>2) Two seems pretty easy to get with speed guessing, you know that # ends in a 9 and it moves quickly from there.</p>

3

<ol>
<li>Turn tx +12y = -3 into the standard y=mx+b form.</li>
</ol>

<p>12y = -tx - 3 <----y=mx+b</p>

<p>M is the slope, or in this case, -tx.</p>

<p>We isolate the Y.
y==tx/12 - 3 / 12</p>

<p>now, -tx/12 is the slop, and the slope is said to be -10. </p>

<p>so -tx/12 = 10
10 X 12 = t
t= 120.</p>

<ol>
<li> <a href="http://talk.collegeconfidential.com/sat-preparation/543271-2-math-questions.html%5B/url%5D"&gt;http://talk.collegeconfidential.com/sat-preparation/543271-2-math-questions.html&lt;/a&gt;&lt;/li>
</ol>

<p>^^^ best explanation.</p>

4

<p>Thanks guys, for the quick and concise responses</p>

5

<p>We have a wannabe thug on CC, thats rare.
Yo anytime my n***a</p>

6

<p>^ Rofl lmao ;D</p>