ElectricPavlov

their combined speed is  80 ft /sec

Let's stop one train and say the other is travelling the 80/ft/sec

When their noses touch.....the moving train moves another 15o ft.....then the trains are exactly BESIDE each other

   the moving train needs to move ANOTHER 150 ft to completely pass the other....a total of 300 ft at 80 ft/sec

    300 ft  /   (80 ft/sec)  = 3.75 seconds to completely pass

For payments made at the BEGINNING OF THE MONTH   (payment due annuity)

    ​P=PMT×((1+r)ⁿ−1)/r  ​×  (1+r)​

For payments made at the END OF THE MONTH (ordinary annuity....more common)

   P =PMT X ((1+r)ⁿ  -1)/r       I'll use this one

        PMT = 95      r = 3%/12months = .0025 % per month      n = 10 years * 12 months/year  = 120 months

 P = 95 ( ( 1+.0025)¹²⁰ -1 ) / .0025   =  $ 13 275.43

This is 'completing the square '  exercise'

take 1/2 of the 'x' coefficient     then square it    11^2 = 121

x^2 + 22x + 121    =    (x+11)²

Circumference = pi * d    where d = diameter

circumference/pi = d      

circumference/2pi  = radius

Area = pi r^2   = pi   *( circumference/2pi)^2

                       = pi ( 15pi/2pi)^2

                       = pi * (15/2)^2    = 225/4  pi =56.25 pi  cm²

Varies inversly  means   a² ~ 1/b³     or more correctly    a² = k/b³    where k is a 'proportionality constant'

Sub in the values given to find the value of 'k'

  (7)^2 = k/(3^3)

49 = k/27

k = 1323

So    a^2 = 1323/b^3     now sub in the question numbers to find a^2

         a^2 = 1323/(6^3)    = 6.125

Just divide x^2 + 2x + 3      into    2x^5 + 3x^4 + 8x^3 + 8x^2 + 18x + 9        can you do that?

3x^2−18x=30y−3y^2      re=arrange

3x^2 - 18 x       + 3y^2-30y      = 0  divide through by 3

x^2-6x           + y^2-10y            = 0*  'complete the sqaure' for x and y

(x-3)^2           +(y-5)^2       =   9 + 25

(x-3)^2    + (y-5)^2 = 34                       this is standard form of a circle where r^2 = 34       then r = sqrt34     diameter = 2r = 2 sqrt34

The first one is not wrong....you just didn't read  my answer and finish the work    251.33 cm   IS  2.5133 m      Don't be lazy !!!

The second one is correct too.....perhaps you did not enter the question correctly...??

how many times must the wheel rotate completely in order for pierre to travel 11m?     Maybe you meant 100 m   not 11 m ?

Circumference of circle = pi * d

                                      = pi 80   =    251.33 cm

B.      11 m    x     (100 cm/m)    /   (251.33 cm / rotation)  =   4.38 rotations ~~ 4 rotations

IF    y is math 

             x = the answer