<p>I had to use intuition to solve this. whats the algebraic way?</p>
<ol>
<li>In the xy-plane, the graph of the funciton f is a line. if f(2)=7 and f(12)=1, what is the value of f(7)?</li>
</ol>
<p>answer is 4 since i knew that the slope was -3/5... whats the algebraic way?</p>
<p>That’s pretty much the best way. </p>
<p>Find the slope:</p>
<p>(7-1)/(2-12) = -6/10 = -3/5</p>
<p>Then set up the equation</p>
<p>(7-y)/(2-7) = -3/5</p>
<p>Solve for y
The answer is indeed 4.</p>
<p>The easy way is if you can see that 7 is halfway between 2 and 12, then you know the value of f(7) is halfway between those of f(2) and f(12).</p>
<p>my reasoning was same as ^.</p>