X=weekly allowance
x/2=money saved (= money spent).
We can suggest this equation:
x/2+4=12
lowest common multiple=2
x+8=24
x=24-8
x=16
Answer: her weekly allowance is $16.
If (x-24)0.25 = 4, distribute 0.25 within the parenthesis.
0.25x - 6 = 4
0.25x = 10
Divide both sides by 0.25
x = 40
Get the y by itself
-2y= -3x + 1
Divide -2 to everything
y= 3/2x - 1/2
Other equation (get y by itself)
-6y= -9x + 3
y=3/2x - 1/2
Use substitution
3/2x-1/2=3/2-1/2
0=0
All real numbers (any value of x makes the equation true)
Answer:
Transformation 3 across to the right and -7 down.
Answer:

Now we can find the second central moment with this formula:

And replacing we got:

And the variance is given by:
![Var(X) = E(X^2) - [E(X)]^2](https://tex.z-dn.net/?f=%20Var%28X%29%20%3D%20E%28X%5E2%29%20-%20%5BE%28X%29%5D%5E2)
And replacing we got:

And finally the deviation would be:

Step-by-step explanation:
We can define the random variable of interest X as the return from a stock and we know the following conditions:
represent the result if the economy improves
represent the result if we have a recession
We want to find the standard deviation for the returns on the stock. We need to begin finding the mean with this formula:

And replacing the data given we got:

Now we can find the second central moment with this formula:

And replacing we got:

And the variance is given by:
![Var(X) = E(X^2) - [E(X)]^2](https://tex.z-dn.net/?f=%20Var%28X%29%20%3D%20E%28X%5E2%29%20-%20%5BE%28X%29%5D%5E2)
And replacing we got:

And finally the deviation would be:
