Im not sure but i think its 1.22474487
sorry just in case its wrong :(
Answer:
Rational
Step-by-step explanation:
A rational number can be written as a fraction of the form.

and a and b are integers.

Hence in this case a=999 and b=100.
Since both are integers with b being a non-zero integer, we conclude that 9.99 is a rational number.
Answer:
0
Step-by-step explanation:
We find the determinant of a matrix by the method below. If we have a matrix:
![\left[\begin{array}{cc}a&b\\c&d\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7Da%26b%5C%5Cc%26d%5Cend%7Barray%7D%5Cright%5D)
The determinant is 
Now, using cramer's rule, we find x-value by the formula:

Where D is the determinant of the original problem and
is the determinant of the x-value matrix. How do we get those?
<u><em>To get original matrix and thus D, we set up the matrix as the coefficients of x and y (s) of both the equations and to get matrix of x-value and thus
, we replace the x values of the matrix with the numbers in the right hand side of the 2 equations.</em></u> We show this below:
<em />
<em>To get D:</em>
![\left[\begin{array}{cc}3&4\\1&-6\end{array}\right] \\D=(3)(-6)-(1)(4)=-18-4=-22](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bcc%7D3%264%5C%5C1%26-6%5Cend%7Barray%7D%5Cright%5D%20%5C%5CD%3D%283%29%28-6%29-%281%29%284%29%3D-18-4%3D-22)
<em>To get
:</em>
<em>
</em>
<em />
<em>Putting into the formula, we get:</em>
<em>
</em>
<em />
<em>Thus, the value of x is 0</em>