Arock is launched from a cannon. it's height, h (x), can be represented by a quadratic function in terms of time, x, in seconds.

after 1 second, the rock is 243 feet in the air
after 2 seconds, the rock is 452 feet in the air

find the height, in feet, of the rock after 5 seconds.

now, we know the cannon is on the ground, thus hₒ is 0
we also know the -16, in case you're wondering, that's the gravity acceleration in feet divided by 2

what we dunno is vₒ, or the initial velocity

however, let's use those values given



so, with every passing second, the initial velocity is dropping by 1 foot
after 1 it was 259, then after 2 seconds it became 258

if that continues, after 5 seconds, it'll be 255

so, now if we make t=5 and vₒ=255

then we end up with   

You just divide and you will find x