If you have a quadratic equation such as



you realize that the solutions to that equation
is the solution to this system of equations:



The line whose equation is y=0 is the x-axis.

So you graph the first equation, then look to
see the values of x where the graph crosses the
x-axis.

So the answer is "the x-intercepts" or
"the values of x at which the graph crosses the
x-axis.

Example:

Solve the quadratic equation:



The solutions to this are the x-values of the
solution to:



So we graph the first equation by finding
points:

(-2,11), (-1,9), (0,-21), (1,-25), (2,-21), (3,-9), (4,11)



You can see the solutions to 
by observing that the graph crosses the x-axis
at  and at .

So those are the solutions to .

Edwin