I got 11.6

Not sure if its right FG to whoever has the right answer or can confirm

quit posting new topics. stick to one of them

Similar to the other one you just have to recognize what the "B" and "C" terms are in the basic quadratic given y = ax^2 +bx + c

in that sense these questions are more "physics based" (I've never seen a problem like this in an algebra class) but

here h0 (intial height) will be 43 since ittells you you're on a platform 43 ft off the ground
v0 is the initial velocity (how "hard" you threw the ball) and its 189 ft /s


so your quadratic is h = -16t^2 + 189t + 43

the arrow hits the ground when height = 0

so we plug in 0

0 = -16t^2 +189t +43

I'm sure you can fiure out the answer from here with the quadratic eqn

This post was edited by nlin on Nov 24 2013 08:28pm

For the last one I got 70.2 not sure if its right or wrong

Sqrt(x^2+(14+x)^2) = 90
2x^2 + 28x + 196 = 8100
x^2 + 14x + 98 = 4050
x^2 + 14x - 3952 = 0
x = sqrt(4001) + 7 (neglect negative root)
x = 70.25<- This is Lisa's speed
Brad's speed would be 84.25 mph
To the nearest tenth is 84.3 mph

If we set up the first equation to be sqrt(x^2+(x-14)^2)=90 then x would have been brad's speed

This post was edited by Dontrunaway on Nov 24 2013 09:35pm

There is a mistake on this line, the solution would be
x = -1*(sqrt(4001) + 7)
and
x = sqrt(4001) + 7

disregard the first answer (the negative one), and we have the speed approximately 56.25 mph and the other speed approx 70.25

Yeah i got it I had to re arrange some things.. im still working on this lesson.. 4 hours now >.<

r = revenue
s = number of tv's sold
p = price of tv

r{s,p}=s*p
r{p} = (130 - 2*p)*p

dr/dp = 130 - 4p = 0
p = $32.50

r{32.50} = $2112.50

This post was edited by Rocinante on Nov 24 2013 10:46pm