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