Question

what are the solutions for x?
3x^2=-9x

Answer 1

x = -3
x = 0
3x2 + 9x = 0
use quadratic formula to calculate x1 and x2

Answer 2

\[x1,x2 = (-b \pm \sqrt{b^2-4ac})/2a\]
a = 3
b=9
c = 0
if 2 roots = two intersection points for the parabola
1 root = one
0 = no roots, parabola doesnt intercept the axis