Answer:
and 
Step-by-step explanation:
First of all, even if the system is of 4th degree, by looking at the shape of the equations I am expecting up to 2 solutions.
The easiest way to solve it, since both equation are in the form y= something, is to equate both RHSs.

which tells us that either
or 
Now we can replace these value of x in one of the two to finish our work: 

The figure has 5 sides, so it must be a pentagon. Pentagon’s interior angles sum up to 540°.
Therefore:
132+90+3x=540
222+3x=540
3x=318
x=106
Checking work, where x=106
222+3(106)=540.
So x°=106°
Answer:
130
Step-by-step explanation:
You want the determinant of the matrix ...
![\left[\begin{array}{ccc}4&3&2\\-3&1&5\\-1&-4&3\end{array}\right]](https://tex.z-dn.net/?f=%5Cleft%5B%5Cbegin%7Barray%7D%7Bccc%7D4%263%262%5C%5C-3%261%265%5C%5C-1%26-4%263%5Cend%7Barray%7D%5Cright%5D)
One way to figure it is as the difference between the sum of products of the down-diagonals and the sum of products of the up-diagonals:
D = (4)(1)(3) +(3)(5)(-1) +(2)(-3)(-4) -(-1)(1)(2) -(-4)(5)(4) -(3)(-3)(3)
= 12 -15 +24 +2 +80 +27
D = 130
The determinant of the coefficient matrix is 130.
_____
Many scientific and graphing calculators and web sites can perform this calculation for you.