<p>How do you solve these types of problems? </p>
<p>Question: In the x-y coordinate system, ( square rooot 6, k) is one of those points of intersections of the graphs y= x^2-7 and y = -x^2 + j where j is a constant. What is the value of j? </p>
<p>(A) 5
(B) 4
(c) 3
(D) 2
(E) 1 </p>
<p>Thank you for your help!</p>
<p>The two equations INTERSECT, meaning the point (sqrt(6),k) is common to both.</p>
<p>Plugin Sqrt(6) into the y=x^2 -7 to get -1. So the point is (sqrt(6),-1).</p>
<p>Using that info, find J!</p>
<p>Into the other equation:
-1=-6 + J
J= 5</p>
<p>Agreed^ remember that for lines that intersect, the X and Ys are the same for both equations. Just pug one point, whether its Y or X, and solve for the other.</p>
<p>Alternate (ever so slightly) way:
x^2-7 = -x^2+j
Plugging x=sqrt(6)
6-7 = -6+j
j = 5</p>