Identify any solutions to the system given below.

[tex]\[
\begin{array}{l}
2x + y = 5 \\
3y = 15 - 6x
\end{array}
\][/tex]

A. [tex]\((6, -7)\)[/tex]
B. [tex]\((2, 1)\)[/tex]
C. [tex]\((-2, -9)\)[/tex]
D. [tex]\((-4, 13)\)[/tex]



Answer :

To identify which of the given points satisfy the system of equations, we need to solve the system:

[tex]\[ \begin{array}{l} 2x + y = 5 \\ 3y = 15 - 6x \end{array} \][/tex]

First, solve the second equation for [tex]\( y \)[/tex]:

[tex]\[ 3y = 15 - 6x \][/tex]

Divide both sides by 3 to isolate [tex]\( y \)[/tex]:

[tex]\[ y = 5 - 2x \][/tex]

Next, substitute [tex]\( y = 5 - 2x \)[/tex] into the first equation:

[tex]\[ 2x + (5 - 2x) = 5 \][/tex]

Combine like terms:

[tex]\[ 2x + 5 - 2x = 5 \][/tex]

[tex]\[ 5 = 5 \][/tex]

This is always true, which means the two equations are essentially the same and the system has infinitely many solutions along the line [tex]\( y = 5 - 2x \)[/tex].

We now need to check which of the given points lie on this line:

1. For the point [tex]\( (6, -7) \)[/tex]:

[tex]\[ y = 5 - 2x \implies -7 = 5 - 2(6) \implies -7 = 5 - 12 \implies -7 = -7 \][/tex]

This point satisfies the equation.

2. For the point [tex]\( (2, 1) \)[/tex]:

[tex]\[ y = 5 - 2x \implies 1 = 5 - 2(2) \implies 1 = 5 - 4 \implies 1 = 1 \][/tex]

This point satisfies the equation.

3. For the point [tex]\( (-2, -9) \)[/tex]:

[tex]\[ y = 5 - 2x \implies -9 = 5 - 2(-2) \implies -9 = 5 + 4 \implies -9 = 9 \][/tex]

This point does not satisfy the equation.

4. For the point [tex]\( (-4, 13) \)[/tex]:

[tex]\[ y = 5 - 2x \implies 13 = 5 - 2(-4) \implies 13 = 5 + 8 \implies 13 = 13 \][/tex]

This point satisfies the equation.

After checking all the points, the solutions to the system of equations among the given points are:

[tex]\[ (6, -7), (2, 1), \text{and} (-4, 13) \][/tex]