ElectricPavlov

x^2 = 2x+48

x^2-2x-48 = 0     x= 8 or -6    (via Quadratic Formula)

Your Q asks for the LOWER bound of AREA

  You need to find the lowerst values that will round to    15.8    and   5.2        which would be 15.75  and 5.15 cm respectively, then:

Lower limit for AREA  would be   15.75 x 5.15 =    .......    cm2

Of course it is wrong......you didn't do the work did you?  I gave you the LOWER limit of perimeter as an EXAMPLE.....you just typed in the answer didn't you?

Lower limit for AREA  would be   15.75 x 5.15 =    .......    cm²

I showed how to obtain the LOWER limit PERIMETER as an EXAMPLE to you ....YOU were supposed to do the UPPER limit of PERIMTER.....

Wow...I just saw the speed of the train was given as 120 m/s

then   2 seconds to fully enter =  240 m train length

           3 seconds for back of train to exit = 360 m tunnel length

240/360 = 2/3     (same answer...I just wanted to use the given numbers) 

train takes 2 seconds to fully enter the tunnel      it still takes one more second for the front of train to reach the exit....and another two seconds for the back of the train to exit the tunnel

let's say it is travelling at 100 m/s

2 seconds to enter fully  =   2 s x 100m/s = 200m     this is how long the train is

3 seconds later the back of the train travels  300 m    and exits the tunnel      tunnel length = 300 m

length of train / length of tunnel   =   200/300  =   2/3

Example   LOWER bound 

   the dimensions COULD be  15.75   (rounds to 15.8)       and 5.15 (rounds to 5.2)

        lower bound for perimeter could be   2 x (15.75 + 5.15) = 41.8  cm

F = 24d =  71

F + 22d  =  68    Subtract this equation from the first

        2d = 3

          d = 3/2  =  $1.50 / day      now use this value of 'd' in either one of the equations to compute 'F' 

ONE revolution is 2 pi radians

3.6 rev / 6 s   x   60 s / /1 min     x   2 pi rad /rev   = 3.6 /6     x 60    x   2 pi  = ......... Radians/min    (leave 'pi' in your answer )

Yes...I've seen nuurses make mistakes when a curve is tosses at them and a drug all of a sudden comes with a different concentration/strength.  They have infusion pumps now in which you enter all of the parameters and it will calculate the infusion rate for you.....I think they just do that and assume they got it all correct wiithout knowing the method the infusion rate is calculated...kinda scary, but they woud often ask me if everything looked 'OK"......

   Perhaps you heard of the 'rule of sixes'   'point sixes'   etc when mixing or compounding infusions so that the ml/hr displayed on the pump was

mg/kg /min etc ? 

y = .65 %  = .0065

.0065 = [100(.02) + x(.005) ] /(100+x)      ( your question has the equation incorrectly written)

.0065 (100+x)   =  2 + .005x

.65 +.0065x = 2 + .005x

.0015 x = 1.35

x = 900 ml  of    .5 % solution