<p>
[quote]
k = 6n and 36 = n^2.
[/quote]
That's the part that throws me off. How'd you figure 36=n^2?</p>
<p>I don't know how I got higher math scores than verbal o_O</p>
<p>"36" and "n^2" are the y-intercepts in
y1 = kx + 36
and
y2 = 6nx + n^2.</p>
<p>Now, your turn to enlighten: how do you do html thingies here (quote box, underlining, bold, cursive, whatnot)?</p>
<p>
[quote]
- substitution 4(7+y)=6-2y 28+4y+2y=6 6y=-22 y=-22/6=-11/3</p>
<p>x=7-(11/3)=(22/3)-(11/3)
x=10/3
Answer: D</p>
<p>I don't know how to do the second one..btw is this SAT I MATH?
[/quote]
</p>
<p>You do not have to do excessive arithmetic, I hate terribly that part. Let's manipulate it a bit and we shall get it alright.</p>
<p>x=7+y (1)
4x = 6-2y (2)</p>
<p>deal with (2) first
4x = 2(3-y)
divide both sides you get: </p>
<p>2x = 3-y (3)</p>
<p>Compare (3) and (1) you can see that if you add the two equations together, you eliminate y:</p>
<p>2x = 3-y</p>
<h2>x = 7+y</h2>
<p>3x = 10
x = 10/3</p>
<ol>
<li>x=7+y ==> 2y=2x-14
4x=6-2y ==> 2y=6-4x</li>
</ol>
<p>so, 2x-14=6-4x ==> x=10/3</p>