Answer :

Let's solve the given system of linear equations step-by-step:

[tex]\[ \begin{aligned} &1.\quad x + 2y - z = 3 \quad \text{(Equation 1)} \\ &2.\quad 2x + 4y - 2z = 6 \quad \text{(Equation 2)} \\ &3.\quad -x - 2y + 2 = 6 \quad \text{(Equation 3)} \\ \end{aligned} \][/tex]

First, let's simplify Equation 3:

[tex]\[ -x - 2y + 2 = 6 \implies -x - 2y = 4 \implies x + 2y = -4 \quad \text{(Equation 4)} \][/tex]

Next, let's observe Equations 1 and 2. Notice that Equation 2 is simply twice Equation 1:

[tex]\[ 2(x + 2y - z) = 2 \cdot 3 \implies 2x + 4y - 2z = 6 \][/tex]

This means that Equation 2 does not provide any new information and is redundant.

Hence, we are left with two independent equations:

[tex]\[ \begin{aligned} &1.\quad x + 2y - z = 3 \quad \text{(Equation 1)} \\ &4.\quad x + 2y = -4 \quad \text{(Equation 4)} \end{aligned} \][/tex]

Now, let's subtract Equation 4 from Equation 1 to eliminate [tex]\(x\)[/tex] and [tex]\(y\)[/tex]:

[tex]\[ (x + 2y - z) - (x + 2y) = 3 - (-4) \implies -z = 7 \implies z = -7 \][/tex]

We have found [tex]\(z = -7\)[/tex].

Next, let's substitute [tex]\(z = -7\)[/tex] back into Equation 4 to find [tex]\(x\)[/tex]:

[tex]\[ x + 2y = -4 \quad \text{(Equation 4)} \][/tex]

Since [tex]\(x = -2y - 4\)[/tex], substituting [tex]\(x\)[/tex] we get:

Finally, we only have this relation [tex]\(x = -2y - 4\)[/tex] holding true.

Therefore, the solutions are given by:

[tex]\[ \begin{aligned} &x = -2y - 4, \\ &z = -7 \end{aligned} \][/tex]

Here, [tex]\(y\)[/tex] can be any real number, making [tex]\(x\)[/tex] and [tex]\(z\)[/tex] dependent on [tex]\(y\)[/tex].

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