ElectricPavlov

24-2x >17

-2x > -7

2x < 7

x < 3.5         so   3+ 2+1 = 6 summed

Side lengths are x    xr     and   xr^2

x * x^r * xr^2 = 216

x^3 r^3 = 216

xr = 6      and     6/r = x

and    

2 (x*xr) + 2 (xr*xr^2) + 2 ( xr^2 * x) = 312

12x          + 12xr^2    +   2 x^2 r^2

72/r          + 72 r         +   72  = 312

72            + 72 r^2      + 72r   = 312 r

72r^2   - 240 r  + 72  = 0 

    Quadratic Formula shows r = 3           then x = 2        xr = 6     xr^2 = 18 cm

d + 4 *9   =  0 + d *7

d + 36 = 7d

d = 6     so n = 42 ₁₀

Here is a diagram to get you started:

See the very similar (but not EXACTLY the same) question/ answer here:

https://web2.0calc.com/questions/2-parabola-questions

The axis of symmetry is just that....the axis of symmetry....so the zeroes are equal distances from the axis ...but on opposite sides

    on zero is  15,0     then the axis of symmetry is   x = 12  then the other zero is 9,0

you are given two zeroes   x = -3    and x = 5

so the equation becomes   y = (x+3)(x-5)        expand to the form requested ....

Here is one way (see image below)

calculate the entire area of the large red rectangle

   then subtract the areas of the right triangles 1 2 3 4   and the square 5   for your answer

It IS wrong....and if you read through the solution YOU should have seen why...there is EIGHT 3's, not seven.....kinda proves you are just looking for answers and not understanding/learning...don't be that guy/girl....

Take each value times it's probability and sum them

3 * 1/10    + 3 * 1/10 ......+ 9* 1/10 + 9 * 1/10 =

8 * 3 * 1/10 + 2 * 9 * 1/10

24/10 + 18/10

= 4.2                         ( in this case it is just the average of all of the slips)

t = 120 + 70 + e

e = 3 out of (3+7)   t  = 3/10 t

t = 120 + 70 + 3/10 t

7/10 t = 190

t = 271.43

e = 3/10 t = 81.43 dollars