X=- 115/24
hope this helps :)
Well, remember
(ab)(cd)=abcd=(ac)(bd)
so
(8t^5)(8t^5)=(8)(t^5)(8)(t^5)=(8*8)(t^5*t^5)=64t^10
83 ft is more than 786 in so it would either be 83 ft > 786 in -or- 786 in < 83 ft
150 is smaller than 200 so 25 is smaller than 40, but 25, in perspective to the numbers, is much smaller than 40. Ana is faster.
Check:
Takashi: 200 divided by 400 equals 5 yd/sec
Ana: 150 divided by 25 equals 6 yd/sec