CPhill

We want the form

4p (y - k)  =  (x - h)^2

Where  the vertex is (-2 ,6+ p)    and  p = ( y coordinate of the focus - y value of the directrix) / 2 =( 4 - 6)/2  = -2/2  = -1

So the vertex  = (-2, 5)  = (h,k)

So we have

4(-1) (y -5)  = ( x - -2)^2    simplify

-4(y - 5) = ( x + 2)^2

-4y + 20  =  x^2 + 4x + 4   subtract 20 from both sides

-4y  = x^2 + 4x - 16          divide through  by  -4

y = (-1/4)x^2  - x  + 4

Here's the graph : https://www.desmos.com/calculator/1khnfskw3p

Distance / Time  = Rate   .....so......

30 miles / 26 minutes  =   (15 /13)  miles per minute  →  90/78 miles per minute

And 70 mph  =  ( 7/6)  miles per minute →   91/78 miles per minute

So......70 mph  is fast enough

If you have the side length of the square, the area is

pi * (√2 * side / 2)^2 =  pi * (side^2) / 2

If given the diagonal length of the square

pi * (diagonal / 2) ^2

Post your problem....we'll see what we can do.....

√1089  =  33

3n-5=19      add 5 to both sides

3n  =  24     divide both sides by 3

n  =  8

a )  P (> 20)  =  470 / 10000 =  .047  = 4.7%

b )    P ( no more than 10)  =  [ 1382 + 2350 + 2010] / 10000  = .5742  = 57.42 %

Thanks, Alan......here's another approach

Common difference  =   [ 29th term - 3rd term] / [ 29 - 3 ]  =

 [ 289 - 29 ] / [ 29 - 3 ]  =

260 / 26  =   10

So....the fifth term is

29 + 2(10)  =  49

Here's a slightly different approach :

We have 4 ways to choose the placement of the X in the first row

Then, we have 2 ways to choose the placement of the X in the second row.....choose either column in the box  not occupied by the first  X 

Then we have 2  ways  to choose the placement of the X in the third row......choose either column not occupied by the first  two X's

And we only have 1 remaining choice of boxes in the last row

So...

4 * 2 * 2 * 1   =   16 ways

P (4 and <5)  =  (1/6) (1/4)  =  1/24