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
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