Completing the square........... (+25 points+!) Someone please help:)

Answer:
D)
[tex]5 \times {10}^{ - 12} [/tex]
Step-by-step explanation:
velocity(v) = distance/time
but distance =
[tex]3 \times {10}^{ - 4} [/tex]
and velocity =
[tex]6 \times {10}^{7} [/tex]
[tex]6 \times {10}^{7} = \frac{3 \times {10}^{ - 4} }{time} [/tex]
[tex]time = \frac{3 \times {10}^{ - 4} }{6 \times {10}^{7} } [/tex]
[tex]time = 5 \times {10}^{ - 12} [/tex]