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<li>In the xy plane line L passes through the origin and is perpendicular to the line 4x = y = k, where k is a constant . if two lines intersect at (t, t + 1) what is the value of t?</li>
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<p>Okay i UNDERSTAND HOW PEOPLE GOT THE ANSWER A) - 4/3 BY PLUGGING IN (t, t+ 1) into y = 1/4x ( the line perpendicular to y = - 4x) BUT</p>

<p>WHY CANT I PLUG IN (t , t + 1 ) INTO y = -4x and get the answer? It comes out to - 1/5 or something</p>

<p>y do i have to plug it into the perpendicular line y not the other line since they BOTH intersect at that point</p>

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<p>the line perpendicular from what i am reading does not have to pass through the origin. In fact it can't since the two lines already interesect at t,t+1 there can't be another point where they intersect unless they are parallel, which they are not. Basically you don't know the y-intercept of the like with -4 slope.</p>