Select the correct answer.

For which system of inequalities is [tex]$(3,-7)$[/tex] a solution?

A.
[tex]\[
\begin{array}{l}
x + y \ \textless \ -4 \\
3x + 2y \ \textless \ -5
\end{array}
\][/tex]

B.
[tex]\[
\begin{array}{l}
x + y \leq -4 \\
3x + 2y \ \textless \ -5
\end{array}
\][/tex]

C.
[tex]\[
\begin{array}{l}
x + y \ \textless \ -4 \\
3x + 2y \leq -5
\end{array}
\][/tex]

D.
[tex]\[
\begin{array}{l}
x + y \leq -4 \\
3x + 2y \leq -5
\end{array}
\][/tex]



Answer :

To determine for which system of inequalities the point [tex]\((3, -7)\)[/tex] is a solution, we will check each system individually.

First, let's assign the values of the point to the variables [tex]\( x \)[/tex] and [tex]\( y \)[/tex]:
[tex]\[ x = 3 \][/tex]
[tex]\[ y = -7 \][/tex]

Now let's examine each system:

System A:
[tex]\[ \begin{array}{l} x + y < -4 \\ 3x + 2y < -5 \end{array} \][/tex]

Substituting [tex]\( x = 3 \)[/tex] and [tex]\( y = -7 \)[/tex] into the inequalities:
[tex]\[ 3 + (-7) < -4 \][/tex]
[tex]\[ -4 < -4 \quad \text{(False)} \][/tex]
For the second inequality:
[tex]\[ 3(3) + 2(-7) < -5 \][/tex]
[tex]\[ 9 - 14 < -5 \][/tex]
[tex]\[ -5 < -5 \quad \text{(False)} \][/tex]

Since the first inequality is false, [tex]\((3, -7)\)[/tex] is not a solution to System A.

System B:
[tex]\[ \begin{array}{l} x + y \leq -4 \\ 3x + 2y < -5 \end{array} \][/tex]

Substituting [tex]\( x = 3 \)[/tex] and [tex]\( y = -7 \)[/tex] into the inequalities:
[tex]\[ 3 + (-7) \leq -4 \][/tex]
[tex]\[ -4 \leq -4 \quad \text{(True)} \][/tex]
For the second inequality:
[tex]\[ 3(3) + 2(-7) < -5 \][/tex]
[tex]\[ 9 - 14 < -5 \][/tex]
[tex]\[ -5 < -5 \quad \text{(False)} \][/tex]

Since the second inequality is false, [tex]\((3, -7)\)[/tex] is not a solution to System B.

System C:
[tex]\[ \begin{array}{l} x + y < -4 \\ 3x + 2y \leq -5 \end{array} \][/tex]

Substituting [tex]\( x = 3 \)[/tex] and [tex]\( y = -7 \)[/tex] into the inequalities:
[tex]\[ 3 + (-7) < -4 \][/tex]
[tex]\[ -4 < -4 \quad \text{(False)} \][/tex]
For the second inequality:
[tex]\[ 3(3) + 2(-7) \leq -5 \][/tex]
[tex]\[ 9 - 14 \leq -5 \][/tex]
[tex]\[ -5 \leq -5 \quad \text{(True)} \][/tex]

Since the first inequality is false, [tex]\((3, -7)\)[/tex] is not a solution to System C.

System D:
[tex]\[ \begin{array}{l} x + y \leq -4 \\ 3x + 2y \leq -5 \end{array} \][/tex]

Substituting [tex]\( x = 3 \)[/tex] and [tex]\( y = -7 \)[/tex] into the inequalities:
[tex]\[ 3 + (-7) \leq -4 \][/tex]
[tex]\[ -4 \leq -4 \quad \text{(True)} \][/tex]
For the second inequality:
[tex]\[ 3(3) + 2(-7) \leq -5 \][/tex]
[tex]\[ 9 - 14 \leq -5 \][/tex]
[tex]\[ -5 \leq -5 \quad \text{(True)} \][/tex]

Since both inequalities are true, [tex]\((3, -7)\)[/tex] is a solution to System D.

Hence, the correct answer is:
[tex]\[ \boxed{4} \][/tex]