Answer:
To solve the given system of equations using Gaussian elimination, let's rewrite the equations in matrix form:
```
[ 2 1 1 ] [ X ] [ 4 ]
[ 0 1 -0.1] * [ Y ] = [ 0.4]
[ 3 2 1 ] [ Z ] [ 2 ]
```
Performing Gaussian elimination:
1. Row 2 = Row 2 - 0.1 * Row 1
```
[ 2 1 1 ] [ X ] [ 4 ]
[ 0 0 0 ] * [ Y ] = [ 0 ]
[ 3 2 1 ] [ Z ] [ 2 ]
```
2. Row 3 = Row 3 - (3/2) * Row 1
```
[ 2 1 1 ] [ X ] [ 4 ]
[ 0 0 0 ] * [ Y ] = [ 0 ]
[ 0 1/2 -1/2] [ Z ] [ -2 ]
```
3. Row 3 = 2 * Row 3
```
[ 2 1 1 ] [ X ] [ 4 ]
[ 0 0 0 ] * [ Y ] = [ 0 ]
[ 0 1 -1 ] [ Z ] [ -4 ]
```
Now, we have reached an upper triangular form. Let's solve the system of equations:
From the third row, we have Z = -4.
Substituting Z = -4 into the second row, we have 0 * Y = 0, which implies that Y can take any value.
Finally, substituting Z = -4 and Y = k (where k is any arbitrary constant) into the first row, we can solve for X:
2X + 1k + 1 = 4
2X = 3 - k
X = (3 - k) / 2
Therefore, the solution to the system of equations is:
X = (3 - k) / 2
Y = k
Z = -4
Note: The given system of equations in the second part of your question is not clear due to missing operators and formatting issues. Please provide the equations in a clear and properly formatted manner if you need assistance with solving that system.