Question 39613
<pre><font size = 4><b>Write a quadratic equation that has the following two
solutions:
  
x = 4 and x = -9) 

here is my equation

 (x - 4)(x + 9) = 0
  
   x² + 5x - 36 = 0 
 
Substitute y temporarily for 0
and plot this graph

y = x² + 5x - 36


{{{ graph(200, 200, -12, 19, -50, 50, x^2 + 5*x - 36 ) }}}

But since we substituted y for 0, we can only use the two points
on that graph where y actually is 0, and those two points are
(-9,0) and (4,0), where the graph crosses the x-axis. 

Edwin
AnlytcPhil@aol.com</pre>