Two systems of equations are given below. For each system, choose the best description applicable and give the solution.

System A:
[tex]\[
\begin{cases}
2x - y = 6 \\
2x + y = 6
\end{cases}
\][/tex]

A. The system has no solution.
B. The system has a unique solution: [tex]\((x, y) = \square, \square\)[/tex].
C. The system has infinitely many solutions.
They must satisfy the following equation: [tex]\( y = \square \)[/tex].

System B:
[tex]\[
\begin{cases}
4x + y = 4 \\
-4x - y + 4 = 0
\end{cases}
\][/tex]

A. The system has no solution.
B. The system has a unique solution.
C. The system has infinitely many solutions.
They must satisfy the following equation: [tex]\( y = \square \)[/tex].



Answer :

Certainly! Let's analyze each system of equations step-by-step to determine the nature of their solutions.

### System A:
The equations provided are:
1. [tex]\(2x - y = 6\)[/tex]
2. [tex]\(2x + y = 6\)[/tex]

To determine the solution, let's add the two equations:

[tex]\[ \begin{aligned} (2x - y) + (2x + y) &= 6 + 6 \\ 4x &= 12 \\ x &= 3 \end{aligned} \][/tex]

Now that we have [tex]\(x = 3\)[/tex], we substitute this value back into one of the original equations to find [tex]\(y\)[/tex]. Using the first equation:

[tex]\[ \begin{aligned} 2(3) - y &= 6 \\ 6 - y &= 6 \\ y &= 0 \end{aligned} \][/tex]

Thus, the system has a unique solution, which is [tex]\((x, y) = (3, 0)\)[/tex].

### System B:
The equations provided are:
1. [tex]\(4x + y = 4\)[/tex]
2. [tex]\(-4x - y + 4 = 0\)[/tex]

First, let's simplify the second equation to make it easier to compare to the first equation:

[tex]\[ \begin{aligned} -4x - y + 4 &= 0 \\ -4x - y &= -4 \\ 4x + y &= 4 \end{aligned} \][/tex]

Notice that the second equation simplifies to exactly the same as the first equation: [tex]\(4x + y = 4\)[/tex].

When both equations are identical, it means that any solution satisfying the first equation will also satisfy the second equation. Therefore, we have infinitely many solutions parameterized by [tex]\(x\)[/tex].

We can express [tex]\(y\)[/tex] in terms of [tex]\(x\)[/tex] using the equation [tex]\(4x + y = 4\)[/tex]:

[tex]\[ \begin{aligned} 4x + y &= 4 \\ y &= 4 - 4x \end{aligned} \][/tex]

Thus, the system has infinitely many solutions given by the equation [tex]\(y = 4 - 4x\)[/tex].

### Final Answer
[tex]\[ \begin{array}{|l|l|} \hline \text{System A} & \text{} \\ \begin{array}{l} 2x - y = 6 \\ 2x + y = 6 \end{array} & \begin{array}{l} (x, y) = (3, 0) \\ \text{The system has a unique solution.} \end{array} \\ \\ \\ \hline \text{System B} & \text{} \\ \begin{array}{l} 4x + y = 4 \\ -4x - y + 4 = 0 \end{array} & \begin{array}{l} \text{The system has infinitely many solutions.} \\ \text{They must satisfy the following equation:} \\ y = 4 - 4x \end{array} \\ \hline \end{array} \][/tex]