Answer:
Step-by-step explanation:
The given system is:
Since I prefer to use smaller numbers I'm going to divide both sides of the first equation by 3 and both sides of the equation equation by 6.
This gives me the system:
We could solve the first equation for 
and replace the second with that.
Let's do that.
Subtract 
on both sides:
So we are replacing the second in the second equation with 
which gives us:
Now recall the first equation we arranged so that was the subject. I'm referring to .
We can now find given that using the equation .
Let's do that.
with :
So the solution is (8,-1).
We can check this point by plugging it into both equations.
If both equations render true for that point, then we have verify the solution.
Let's try it.
with 
:
is a true equation so the "solution" looks promising still.
with :
is also true so the solution has been verified since both equations render true for that point.
Answer:
3. Standard deviation is the square root of the variance.
4. Standard deviation is useful because it has the same units as the underlying data.
Step-by-step explanation:
3. In statistics, the dispersion in a given data with respect to its mean distribution can be determined or measured by standard deviation and variance. The standard deviation of a distribution can also be determined as the square root of variance.
4. Standard deviation is measured in the same units as that of the original data. Thus it has the same units as the underlying data.
Theres not really a way to show that on here unless i draw you a picture...you must know that 10 thousandths is equal to 1 hundredth. if you draw a 100 by 100 centimeter square on graph paper it will consist of a thousand squares since 100 x 100 is 1000, and if you colored in 10 of those squares, it would be 10 thousandths
