IDNLearn.com: Where your questions meet expert answers and community support. Our experts provide timely, comprehensive responses to ensure you have the information you need.

Solve the system of linear equations and check any solutions algebraically. (If there is no solution, enter "NO SOLUTION". If there are infinitely many solutions, express [tex]$x$, [tex]$y$[/tex], and $z$[/tex] in terms of the real number [tex][tex]$a$[/tex][/tex].)

[tex]\[
\begin{cases}
x + y + z = 14 \\
2x - y + z = 17 \\
3x - z = 7
\end{cases}
\][/tex]

[tex](x, y, z) = (\square)[/tex]


Sagot :

To solve the given system of linear equations:

[tex]\[ \begin{cases} x + y + z = 14 \\ 2x - y + z = 17 \\ 3x - z = 7 \\ \end{cases} \][/tex]

we will find the values of [tex]\(x\)[/tex], [tex]\(y\)[/tex], and [tex]\(z\)[/tex].

### Step 1: Solve for [tex]\(z\)[/tex] from the third equation
Start with the third equation:
[tex]\[ 3x - z = 7 \][/tex]

Rearrange to solve for [tex]\(z\)[/tex]:
[tex]\[ z = 3x - 7 \][/tex]

### Step 2: Substitute [tex]\(z\)[/tex] into the first two equations
Now substitute [tex]\(z = 3x - 7\)[/tex] into the first and second equations.

#### First equation:
[tex]\[ x + y + (3x - 7) = 14 \][/tex]
Simplify:
[tex]\[ x + y + 3x - 7 = 14 \][/tex]
[tex]\[ 4x + y - 7 = 14 \][/tex]
[tex]\[ 4x + y = 21 \][/tex]
[tex]\[ y = 21 - 4x \][/tex] \quad [tex]\((1)\)[/tex]

#### Second equation:
[tex]\[ 2x - y + (3x - 7) = 17 \][/tex]
Simplify:
[tex]\[ 2x - y + 3x - 7 = 17 \][/tex]
[tex]\[ 5x - y - 7 = 17 \][/tex]
[tex]\[ 5x - y = 24 \][/tex]
[tex]\[ y = 5x - 24 \][/tex] \quad [tex]\((2)\)[/tex]

### Step 3: Equate the expressions for [tex]\(y\)[/tex]
From equations [tex]\((1)\)[/tex] and [tex]\((2)\)[/tex]:
[tex]\[ 21 - 4x = 5x - 24 \][/tex]

Solve for [tex]\(x\)[/tex]:
[tex]\[ 21 + 24 = 5x + 4x \][/tex]
[tex]\[ 45 = 9x \][/tex]
[tex]\[ x = 5 \][/tex]

### Step 4: Find [tex]\(y\)[/tex] using [tex]\(x = 5\)[/tex]
Substitute [tex]\(x = 5\)[/tex] into [tex]\(y = 21 - 4x\)[/tex]:
[tex]\[ y = 21 - 4(5) \][/tex]
[tex]\[ y = 21 - 20 \][/tex]
[tex]\[ y = 1 \][/tex]

### Step 5: Find [tex]\(z\)[/tex] using [tex]\(x = 5\)[/tex]
Substitute [tex]\(x = 5\)[/tex] into [tex]\(z = 3x - 7\)[/tex]:
[tex]\[ z = 3(5) - 7 \][/tex]
[tex]\[ z = 15 - 7 \][/tex]
[tex]\[ z = 8 \][/tex]

Therefore, the solution to the system of equations is:
[tex]\[ (x, y, z) = (5, 1, 8) \][/tex]

### Step 6: Check the solution
Substitute [tex]\(x = 5\)[/tex], [tex]\(y = 1\)[/tex], and [tex]\(z = 8\)[/tex] back into the original equations:
1. [tex]\( x + y + z = 14 \)[/tex]
[tex]\[ 5 + 1 + 8 = 14 \][/tex]
[tex]\[ 14 = 14 \quad \text{(True)} \][/tex]

2. [tex]\( 2x - y + z = 17 \)[/tex]
[tex]\[ 2(5) - 1 + 8 = 17 \][/tex]
[tex]\[ 10 - 1 + 8 = 17 \][/tex]
[tex]\[ 17 = 17 \quad \text{(True)} \][/tex]

3. [tex]\( 3x - z = 7 \)[/tex]
[tex]\[ 3(5) - 8 = 7 \][/tex]
[tex]\[ 15 - 8 = 7 \][/tex]
[tex]\[ 7 = 7 \quad \text{(True)} \][/tex]

So, the solution is [tex]\( (x, y, z) = (5, 1, 8) \)[/tex].