<PRE><B>Question 698529</B>
&lt;br&gt;&lt;font face=&quot;Tahoma&quot;&gt;We will let x be the number of times you use the pass,&lt;br&gt;

and let y be the total value left on the pass.&lt;br&gt;

Then we have:&lt;br&gt;

{{{y=-1.5*x+20}}}&lt;br&gt;

The slope of this line is -1.5,&lt;br&gt;

and the y-intercept is 20, or the actual point (0,20)&lt;br&gt;

Graphically, you can see that you will only be able to use the pass about 13 times.&lt;br&gt;

You can also solve that algebraically by setting y equal to zero.&lt;br&gt;&lt;br&gt;

{{{ graph( 600, 600, -24, 24, -24, 24, -1.5x+20 ) }}} &lt;br&gt;&lt;br&gt;

I hope this helps!  Keep practicing!  :)&lt;br&gt;

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