Step-by-step explanation:
i think option a is the correct answer
a)
the average speed, well it does 10 ft in 1.6 secs, so is simply their quotient, 10/1.6 = 6.25 ft/s on average.
b)
over the horizontal, well, it covered horizontally 9.25 ft in those 1.6 secs, so their quotient is 9.25/1.6 = 5.78125 ft/s on average.
c)
we don't know the vertical distance, but

so, it covered vertically about 3.8 ft in those 1.6 secs, so then 3.8/1.6 = 2.375 ft/s on average
Answer: x=3
I got to the answer by doing simple math. Both sides must be even.
5x-4
5(3)-4= 15-4 = 11
x+8
3+8= 11
So x=3