ElectricPavlov

-6i (5+3i)     expand   (remember i = sqrt(-1)    so   i^2 = -1)

-30 i   -18 (i^2)

-18(-1) -30i

18-30i

Since they started with 800 and they triple every 8 hours, I think HOURS would be appropriate.

The last choice   2x^2 + 8x + 22 +  90/(x-4)

Here is my scrawled workings:

y = x^(x-1)     solve for 'x

log (y) = (x-1) log 3

log(y) /log 3 = (x-1)              Remember:   Switching log bases:   Logb(a) =  log(a) / log(b)

log3 (y) = x-1

log3(y) + 1 = x                    Now switch the y's and x's

y = log3(x) + 1

f'(x) = log3(x) + 1

In three-dimensional geometry, skew lines are two lines that do not intersect and are not parallel. A simple example of a pair of skew lines is the pair of lines through opposite edges of a regular tetrahedron.   

( I had to look up that definition)

SO by definition

GC is the only one that fits....the others are parallel or intersect.

- pi/4   (7pi/4)

5 pi /4

ABCD would be the bottom as drawn....it is the face the box would sit on if you placed it on the ground in its present orientation.

Surface area of a cyclinder = circumference x height     (if we are not counting the ends as surface area)

circumference = pi * d  = pi * 2r

SO surface area =  3.14   * 2 (5)   *  10     cm^2         I'll let you plug the numbers....

Let's find the longer leg of the larger triangle first ...this is also the hypotenuse of the smaller triangle

cos 30 = sqrt3 / 2 = adj / hyp = adj/16

adj = 16 sqrt3 / 2   = 8 sqrt3   = hypotenuse of smaller triangle

now for the smaller triangle

cos 30 = adj / hyp  = sqrt 3  / 2  =  adj / (8 sqrt 3)

adj = longer leg =  sqrt 3 / 2  *  8 sqrt 3 =   12 cm   

Thanx, CP.......once in a while I don't make an error!   Haha