Factor f(t) and you can identify the values of t for which the height is zero.
.. f(t) = -16t(t -3)
The projectile lands after 3 seconds in the air. (selection A)
1. 45*x/100=90
x=100*90/45
x=200
2. 24=x/100*52
x=24*100/52≈46,15
4.125=30/100*x
x=125*100/30
x≈416,67
The 4's will cancel out, then we have to get rid of the sqrt(16) on the bottom
sqrt(15) / sqrt(16)
sqrt(16) = 4
final answer = sqrt(15) / 4.
the answer is C
It'd be best if you'd stick to symbols. My interpretation of what you've typed here is 20x - 20x^2 + 5x^3. In descending order by powers of x, that gives us
5x^3 - 20x^2 + 20x.