The x intercept is when y=0. Substitute:
[tex]2x^2+x-21=0[/tex]
Solve for x by factoring.
[tex]2x^2-6x+7x-21=0[/tex]
[tex]=2x(x-3)+7(x-3)=0[/tex]
[tex]=(x-3)(2x+7)=0[/tex]
[tex]x=3[/tex] AND [tex]x=-\frac{7}{2}[/tex]
So therefore, we have our intercepts:
(3,0) & (-7/2,0)
Hope that helped!
~Cam943, Moderator
