Let´s suppose that there are x marbles. 
Then we have the following steps: 
1st child: C1 = 1 + (x-1)/10 
2nd child: C2 = 2 + (x - C1 - 2)/10 
3rd child: C3 = 3 + (x - C1 - C2 - 3)/10 
... 
n-th child: Cn = n + (x - C1 - C2 - ... - C[n-1] - n)/10 

But C1 = C2 = C3 = ... = Cn = k (given by the problem) 

We can rewrite the equations in this way: 
1st child: k = 1 + (x-1)/10 
2nd child: k = 2 + (x - k - 2)/10 
3rd child: k = 3 + (x - 2*k - 3)/10 
... 
n-th child: k = n + (x - (n-1)*k - n)/10 

We must find n. If we choose any two equations, we can find k and x: 
k = 1 + (x-1)/10 
k = 2 + (x - k - 2)/10 
Solving the linear system we find: k=9 and x=81. 
If we try to use the last equation: k = n + (x - (n-1)*k - n)/10 to find the value of n, we will get 0 = 0. So we wont be able to find the value of n with this last equation. Well, we know we have 81 (value of x) marbles. And we know that each child has 9 marbles (value of k). Hence we have 9 children! 

$${\frac{{\mathtt{45}}}{{\mathtt{9}}}}{\mathtt{\,\times\,}}{\mathtt{8}} = {\mathtt{40}}$$

e^.048 = about 1.049

Using the sine inverse, we have

sin^-1 (3/5) = either about 36.87°    ...or about [180 - 36.87] =  143.13°    depending upon which quadrant we're in...

I gave xerxes 3 points, but he made a slight mis-type.....we have

a = (1/2) ( b + 8) 5 

a = (5/2) (b + 8) 

a = (5/2)b + (5/2)(8)  

a =(5/2)b + 40/2

a = (5/2)b + 20

The lateral surface area {area of the "sides" } =

2 * pi * r * h =

2 * pi * 3 * 15 =  90 pi  = about 282.74 sq cm

The min occurs at (0, 0 )

The max occurs at (3, 4)

The total change in temperature was l -10 l + l 18 l = 10 + 18 = 28 degrees

The relative change was -10 + 18   = 8 degrees

I assume this might be...

576=[3/4 ]r^2      multiply both sides by 4/3

576 [4/3] = r^2

768 = r^2      tale both roots

±√768 = r  = about  ± 27.713

What are you trying to do TR, push-start your brain?

If your battery is not dead, it’s much easier to start your brain by taking your mouth out of gear. Doing this will hide your idiocy and fool more people into believing you actually have a functional brain.

Here’s a Roman proverb to consider: Better to keep your mouth shut and have people think you are a fool, than to open it and remove all doubt.

24km  =  24,000m

There are 3600 seconds in one hour

So....

24000 / 3600 = about [6+2/3 ]  m / s

the answer is -7

Let  xy = 7    and x + y = -6    

Using the second equation  we have y = -6 - x

So....substituting this into the first equation, we have

x (-6 - x)  = 7 simplify

-6x - x^2  = 7      rearrange

x^2 + 6x + 7 = 0   using the onsite calculator we have

$${{\mathtt{x}}}^{{\mathtt{2}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{6}}{\mathtt{\,\times\,}}{\mathtt{x}}{\mathtt{\,\small\textbf+\,}}{\mathtt{7}} = {\mathtt{0}} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = {\mathtt{\,-\,}}{\sqrt{{\mathtt{2}}}}{\mathtt{\,-\,}}{\mathtt{3}}\\
{\mathtt{x}} = {\sqrt{{\mathtt{2}}}}{\mathtt{\,-\,}}{\mathtt{3}}\\
\end{array} \right\} \Rightarrow \left\{ \begin{array}{l}{\mathtt{x}} = -{\mathtt{4.414\: \!213\: \!562\: \!373\: \!095}}\\
{\mathtt{x}} = -{\mathtt{1.585\: \!786\: \!437\: \!626\: \!905}}\\
\end{array} \right\}$$

So these are the two interchangeable answers for x and y.......

The area of the equilateral triangle with a side of 8 units is given by :

(1/2)* 8^2* [√3]/ 2  = 64√3

The perimeter is 3 * 8   =  24

So the ratio is:

64√3 / 24 =   [8√3] / 3

The sides of this inscribed square will be 2√2. So the perimeter will be four times this = 8√2

The only whole number I can think of when multiplying is 7 and 1. But when adding even when you change both to negatives the answer will be too big. When you change one to a negative and leave one positive, the answer wouldn't equal 7 when you multiply them together.

like my repsonse dude and ill respond to u, deal?

$${\frac{{\frac{{\mathtt{8}}}{{\mathtt{9}}}}{\mathtt{\,\times\,}}{\mathtt{45}}}{{\mathtt{1}}}} = {\frac{{\mathtt{40}}}{{\mathtt{1}}}} = {\mathtt{40}}$$

DONE

dun dun dun dun dun lol